Beispiel #1
0
class Production(ProtocolInterface):
    """ Production protocol v6

        Production protocol for globular and membrane proteins. You can optionally define a flatbottom potential box and
        atom constraints for the production run.

        An Acemd class object is stored in the Production object which can be used to modify futher options.
        For documentation on further options see :class:`Acemd <htmd.mdengine.acemd.acemd.Acemd>`

        Parameters
        ----------
        runtime : float, default=0
            Running time of the simulation.
        timeunits : str, default='steps'
            Units for runtime. Can be 'steps', 'ns' etc.
        temperature : float, default=300
            Temperature of the thermostat in Kelvin
        fb_k : float, default=0
            Force constant of the flatbottom potential in kcal/mol/A^2. E.g. 5
        fb_reference : str, default='none'
            Reference selection to use as dynamic center of the flatbottom box.
        fb_selection : str, default='none'
            Selection of atoms to apply the flatbottom potential
        fb_box : list, default=[0, 0, 0, 0, 0, 0]
            Position of the flatbottom box in term of the reference center given as [xmin, xmax, ymin, ymax, zmin, zmax]
        useconstantratio : bool, default=False
            For membrane protein simulations set it to true so that the barostat does not modify the xy aspect ratio.
        useconstraints : bool, default=False
            Apply constraints to the production simulation, defined by the constraints parameter
        constraints : dict, default={}
            A dictionary of atomselections and values of the constraint to be applied (in kcal/mol/A^2). Atomselects must be mutually exclusive.
        adaptive : bool, default=False
            Set to True if making production runs for adaptive sampling.
    """
    def __init__(self, _version=2):
        super().__init__()
        self._version = _version
        self._arg(
            'acemd',
            ':class:`Acemd2 <htmd.apps.acemd.Acemd>` or :class:`Acemd <htmd.mdengine.acemd.acemd.Acemd>`'
            ' object', 'Acemd class object', None, val.Object([Acemd2, Acemd]))
        self._arg('runtime', 'float', 'Running time of the simulation.', 25000,
                  val.Number(float, '0POS'))
        self._arg('timeunits', 'str',
                  'Units for runtime. Can be \'steps\', \'ns\' etc.', 'steps',
                  val.String())
        self._arg('temperature', 'float',
                  'Temperature of the thermostat in Kelvin', 300,
                  val.Number(float, 'ANY'))
        self._arg(
            'fb_k', 'float',
            'Force constant of the flatbottom potential in kcal/mol/A^2. E.g. 5',
            0, val.Number(float, 'ANY'))
        self._arg(
            'fb_reference', 'str',
            'Reference selection to use as dynamic center of the flatbottom box.',
            'none', val.String())
        self._arg('fb_selection', 'str',
                  'Selection of atoms to apply the flatbottom potential',
                  'none', val.String())
        self._arg(
            'fb_box',
            'list',
            'Position of the flatbottom box in term of the reference center given as '
            '[xmin, xmax, ymin, ymax, zmin, zmax]', [0, 0, 0, 0, 0, 0],
            val.Number(float, 'ANY'),
            nargs=6)
        self._arg(
            'useconstantratio', 'bool',
            'For membrane protein simulations set it to true so that the barostat '
            'does not modify the xy aspect ratio.', False, val.Boolean())
        self._arg(
            'useconstraints', 'bool',
            'Apply constraints to the production simulation, defined by the '
            'constraints parameter', False, val.Boolean())
        self._arg(
            'constraints', 'dict',
            'A dictionary of atomselections and values of the constraint to be '
            'applied (in kcal/mol/A^2). Atomselects must be mutually exclusive.',
            {}, val.Dictionary(key_type=str))
        self._arg(
            'adaptive', 'bool',
            'Set to True if making production runs for adaptive sampling.',
            False, val.Boolean())
        self._arg(
            'restraints',
            'list',
            'A list of restraint objects. Only works with {}(_version=3),'
            'see :class:`AtomRestraint <htmd.mdengine.acemd.acemd.AtomRestraint>` and'
            ':class:`GroupRestraint <htmd.mdengine.acemd.acemd.GroupRestraint>`'
            ')'.format(self.__class__.__name__),
            None,
            val.Object(_Restraint),
            nargs='*')

        if self._version == 2:
            self.acemd = Acemd2()
            self.acemd.binindex = None
            self.acemd.binvelocities = None
            self.acemd.bincoordinates = 'output.coor'
            self.acemd.extendedsystem = 'output.xsc'
            self.acemd.coordinates = None
            self.acemd.structure = None
            self.acemd.parameters = None
            self.acemd.temperature = None
            self.acemd.restart = 'on'
            self.acemd.restartfreq = '5000'
            self.acemd.outputname = 'output'
            self.acemd.xtcfile = 'output.xtc'
            self.acemd.xtcfreq = '25000'
            self.acemd.timestep = '4'
            self.acemd.rigidbonds = 'all'
            self.acemd.hydrogenscale = '4'
            self.acemd.switching = 'on'
            self.acemd.switchdist = '7.5'
            self.acemd.cutoff = '9'
            self.acemd.exclude = 'scaled1-4'
            self.acemd.scaling14 = '1.0'
            self.acemd.langevin = 'on'
            self.acemd.langevintemp = None
            self.acemd.langevindamping = '0.1'
            self.acemd.pme = 'on'
            self.acemd.pmegridspacing = '1.0'
            self.acemd.fullelectfrequency = '2'
            self.acemd.energyfreq = '5000'
            self.acemd.consref = None
            self.acemd.run = '$numsteps'
            self.acemd.TCL = ('''
set numsteps {NUMSTEPS}
set fb_refindex {{ {REFINDEX} }}
set fb_selindex {{ {SELINDEX} }}
set fb_box {{ {BOX} }}
set fb_K {KCONST}
#
''', '''
proc flatbot1d {x xm xM fb_K} {
  set f 0
  if {$x < $xm} {
    set f [expr $fb_K*[expr $xm-$x]]
  }
  if {$x > $xM} {
    set f [expr $fb_K*[expr $xM-$x]]
  }
  return $f
}
proc calcforces_init {} {
  global ref sel fb_refindex fb_selindex
  berendsenpressure  off
  set ref [addgroup  $fb_refindex]
  set sel [addgroup  $fb_selindex]
}
proc calcforces {} {
  global ref sel fb_K fb_box
  loadcoords coords
##FLATBOTTOM
  if {$fb_K>0} {
    set r0 $coords($ref)
    set r1 $coords($sel)
    set dr  [vecsub $r1 $r0]
    set fx [flatbot1d [lindex $dr 0] [lindex $fb_box 0] [lindex $fb_box 1] $fb_K]
    set fy [flatbot1d [lindex $dr 1] [lindex $fb_box 2] [lindex $fb_box 3] $fb_K]
    set fz [flatbot1d [lindex $dr 2] [lindex $fb_box 4] [lindex $fb_box 5] $fb_K]
    #print "dr: $dr  fx: $fx fy: $fy fz: $fz"
    addforce $sel [list $fx $fy $fz]
  }
}
proc calcforces_endstep { } { }
''')
        elif self._version == 3:
            self.acemd = Acemd()
            self.acemd.binvelocities = None
            self.acemd.bincoordinates = 'output.coor'
            self.acemd.extendedsystem = 'output.xsc'
            self.acemd.coordinates = None
            self.acemd.structure = None
            self.acemd.parameters = None
            self.acemd.restart = 'on'
            self.acemd.trajectoryfile = 'output.xtc'
            self.acemd.trajectoryfreq = 25000
            self.acemd.timestep = 4
            self.acemd.switching = 'on'
            self.acemd.switchdist = 7.5
            self.acemd.cutoff = 9
            self.acemd.thermostat = 'on'
            self.acemd.thermostatdamping = 0.1
            self.acemd.pme = 'on'
        else:
            raise ValueError(
                '_version can not be {}. Choose either 2 or 3.'.format(
                    self._version))

    def _findFiles(self, inputdir):
        # Tries to find default files if the given don't exist
        defaults = {
            'coordinates': ('structure.pdb', ),
            'structure': ('structure.psf', 'structure.prmtop'),
            'parameters': ('parameters', 'structure.prmtop')
        }

        for field in defaults:
            userval = self.acemd.__dict__[field]
            if userval is not None and not os.path.exists(
                    os.path.join(inputdir, userval)):
                raise RuntimeError(
                    'Could not locate file {} set by the user for argument '
                    'Production.acemd.{}'.format(
                        os.path.join(inputdir, userval), field))

            if self.acemd.__dict__[field] is None:
                for val in defaults[field]:
                    if os.path.exists(os.path.join(inputdir, val)):
                        self.acemd.__dict__[field] = val
                        break

            if userval is not None and self.acemd.__dict__[
                    field] is not None and self.acemd.__dict__[
                        field] != userval:
                logger.warning(
                    'Could not locate structure file {}. Using {} instead.'.
                    format(os.path.join(inputdir, userval),
                           os.path.join(inputdir, self.acemd.__dict__[field])))
            elif self.acemd.__dict__[field] is None:
                raise RuntimeError(
                    'Could not locate any {f:} file in {i:}. '
                    'Please set the Production.acemd.{f:} property to '
                    'point to the {f:} file'.format(f=field, i=inputdir))

            if self._version == 2:
                if self.useconstraints and self.acemd.consref is None:
                    self.acemd.consref = self.acemd.coordinates

    def _amberFixes(self):
        # AMBER specific fixes
        if self.acemd.structure.endswith('.prmtop'):
            self.acemd.parmfile = self.acemd.parameters
            self.acemd.parameters = None
            if self._version == 2:
                self.acemd.scaling14 = '0.8333333'
                self.acemd.amber = 'on'

    def _fb_potential2restraints(self, inputdir):
        from moleculekit.molecule import Molecule
        restraints = list()

        fb_box = np.array(self.fb_box)
        # convert fb_box to width
        width = list(
            np.concatenate(
                np.diff(np.array([fb_box[::2], fb_box[1::2]]), axis=0)))

        # If fb_box is not symmetrical
        if not np.all(fb_box[::2] == -fb_box[1::2]):
            # convert fb_box and fb_reference to fbcentre and width
            mol = Molecule(os.path.join(inputdir, self.acemd.structure))
            mol.read(os.path.join(inputdir, self.acemd.coordinates))
            fb_refcentre = mol.get(
                'coords', sel=self.fb_reference).mean(axis=0).squeeze()

            fbcentre = list(
                np.around(
                    np.mean(np.array([fb_box[::2], fb_box[1::2]]), axis=0) +
                    fb_refcentre, 3))
            restraints.append(
                GroupRestraint(self.fb_selection,
                               width, [(self.fb_k, 0)],
                               fbcentre=fbcentre))
        else:
            restraints.append(
                GroupRestraint(self.fb_selection,
                               width, [(self.fb_k, 0)],
                               fbcentresel=self.fb_reference))

        return restraints

    def _constraints2restraints(self):

        restraints = list()
        for constr in sorted(self.constraints):
            restraints.append(
                AtomRestraint(constr, 0, [(self.constraints[constr], 0)]))

        return restraints

    def write(self, inputdir, outputdir):
        """ Writes the production protocol and files into a folder.

        Parameters
        ----------
        inputdir : str
            Path to a directory containing the files produced by a equilibration process.
        outputdir : str
            Directory where to write the production setup files.
        """
        from moleculekit.molecule import Molecule

        # Do version consistency check
        if (self._version == 2 and not isinstance(self.acemd, Acemd2)) and \
                (self._version == 3 and not isinstance(self.acemd, Acemd)):
            raise RuntimeError(
                'Acemd object version ({}) inconsistent with protocol version at instantiation '
                '({})'.format(type(self.acemd), self._version))

        self._findFiles(inputdir)
        self._amberFixes()

        if self._version == 2:
            self.acemd.temperature = str(self.temperature)
            self.acemd.langevintemp = str(self.temperature)
        elif self._version == 3:
            self.acemd.temperature = self.temperature
            self.acemd.thermostattemp = self.temperature

        from htmd.units import convert
        numsteps = convert(self.timeunits,
                           'timesteps',
                           self.runtime,
                           timestep=self.acemd.timestep)
        if self._version == 3:
            self.acemd.run = str(numsteps)

        pdbfile = os.path.join(inputdir, self.acemd.coordinates)
        inmol = Molecule(pdbfile)

        if np.any(inmol.atomselect('lipids')) and not self.useconstantratio:
            logger.warning(
                'Lipids detected in input structure. We highly recommend setting useconstantratio=True '
                'for membrane simulations.')

        if self._version == 2:
            if self.restraints:
                raise RuntimeWarning(
                    'restraints are only available on {}(_version=3)'.format(
                        self.__class__.__name__))
            if self.fb_k > 0:  # use TCL only for flatbottom
                self.acemd.tclforces = 'on'
                if isinstance(self.acemd.TCL, tuple):
                    tcl = list(self.acemd.TCL)
                    tcl[0] = tcl[0].format(
                        NUMSTEPS=numsteps,
                        TEMPERATURE=self.temperature,
                        KCONST=self.fb_k,
                        REFINDEX=' '.join(
                            map(str, inmol.get('index', self.fb_reference))),
                        SELINDEX=' '.join(
                            map(str, inmol.get('index', self.fb_selection))),
                        BOX=' '.join(map(str, self.fb_box)))
                    self.acemd.TCL = tcl[0] + tcl[1]
                else:
                    logger.warning(
                        '{} default TCL was already formatted.'.format(
                            self.__class__.__name__))
            else:
                self.acemd.TCL = 'set numsteps {NUMSTEPS}\n'.format(
                    NUMSTEPS=numsteps)
            if self.useconstraints:
                # Turn on constraints
                self.acemd.constraints = 'on'
                self.acemd.constraintscaling = '1.0'
            else:
                if len(self.constraints) != 0:
                    logger.warning(
                        'You have setup constraints to {} but constraints are turned off. '
                        'If you want to use constraints, define '
                        'useconstraints=True'.format(self.constraints))
        elif self._version == 3:
            if self.restraints is not None:
                logger.info(
                    'Using user-provided restraints and ignoring constraints and fb_potential'
                )
                self.acemd.restraints = self.restraints
            else:
                restraints = list()
                if self.fb_k > 0:
                    logger.warning(
                        'Converting fb_potential to restraints. This is a convenience '
                        'functional conversion. We recommend start using restraints with '
                        '{}(_version=3)'.format(self.__class__.__name__))
                    restraints += self._fb_potential2restraints(inputdir)
                if self.useconstraints:
                    logger.warning(
                        'Converting constraints to restraints. This is a convenience '
                        'functional conversion. We recommend start using restraints with '
                        '{}(_version=3)'.format(self.__class__.__name__))
                    restraints += self._constraints2restraints()
                else:
                    if len(self.constraints) != 0:
                        logger.warning(
                            'You have setup constraints to {} but constraints are turned off. '
                            'If you want to use constraints, define '
                            'useconstraints=True'.format(self.constraints))
                if len(restraints) != 0:
                    self.acemd.restraints = restraints

        if self.useconstantratio:
            self.acemd.useconstantratio = 'on'

        if self.adaptive:
            self.acemd.binvelocities = None

        self.acemd.setup(inputdir, outputdir, overwrite=True)

        if self._version == 2:
            # Adding constraints by writing them to the consref file
            if self.useconstraints:
                inconsreffile = os.path.join(inputdir, self.acemd.consref)
                consrefmol = Molecule(inconsreffile)
                consrefmol.set('occupancy', 0)
                consrefmol.set('beta', 0)
                if len(self.constraints) == 0:
                    raise RuntimeError(
                        'You have set the production to use constraints (useconstraints=True), but have '
                        'not defined any constraints (constraints={}).')
                else:
                    for sel in self.constraints:
                        consrefmol.set('beta', self.constraints[sel], sel)
                outconsreffile = os.path.join(outputdir, self.acemd.consref)
                consrefmol.write(outconsreffile)

    def addConstraint(self, atomselect, factor=1):
        """ Convenience function for adding a new constraint to existing constraints.

        Parameters
        ----------
        atomselect : str
            Atom selection of atoms we want to constrain
        factor : float
            The scaling factor of the constraints applied to the atoms

        Example
        -------
        >>> eq.addConstraint('chain X', 0.3)
        """
        self.constraints[atomselect] = factor
Beispiel #2
0
    def __init__(self, _version=2):
        super().__init__()
        self._version = _version
        self._arg(
            'acemd',
            ':class:`Acemd2 <htmd.apps.acemd.Acemd>` or :class:`Acemd <htmd.mdengine.acemd.acemd.Acemd>`'
            ' object', 'Acemd class object', None, val.Object([Acemd2, Acemd]))
        self._arg('runtime', 'float', 'Running time of the simulation.', 25000,
                  val.Number(float, '0POS'))
        self._arg('timeunits', 'str',
                  'Units for runtime. Can be \'steps\', \'ns\' etc.', 'steps',
                  val.String())
        self._arg('temperature', 'float',
                  'Temperature of the thermostat in Kelvin', 300,
                  val.Number(float, 'ANY'))
        self._arg(
            'fb_k', 'float',
            'Force constant of the flatbottom potential in kcal/mol/A^2. E.g. 5',
            0, val.Number(float, 'ANY'))
        self._arg(
            'fb_reference', 'str',
            'Reference selection to use as dynamic center of the flatbottom box.',
            'none', val.String())
        self._arg('fb_selection', 'str',
                  'Selection of atoms to apply the flatbottom potential',
                  'none', val.String())
        self._arg(
            'fb_box',
            'list',
            'Position of the flatbottom box in term of the reference center given as '
            '[xmin, xmax, ymin, ymax, zmin, zmax]', [0, 0, 0, 0, 0, 0],
            val.Number(float, 'ANY'),
            nargs=6)
        self._arg(
            'useconstantratio', 'bool',
            'For membrane protein simulations set it to true so that the barostat '
            'does not modify the xy aspect ratio.', False, val.Boolean())
        self._arg(
            'useconstraints', 'bool',
            'Apply constraints to the production simulation, defined by the '
            'constraints parameter', False, val.Boolean())
        self._arg(
            'constraints', 'dict',
            'A dictionary of atomselections and values of the constraint to be '
            'applied (in kcal/mol/A^2). Atomselects must be mutually exclusive.',
            {}, val.Dictionary(key_type=str))
        self._arg(
            'adaptive', 'bool',
            'Set to True if making production runs for adaptive sampling.',
            False, val.Boolean())
        self._arg(
            'restraints',
            'list',
            'A list of restraint objects. Only works with {}(_version=3),'
            'see :class:`AtomRestraint <htmd.mdengine.acemd.acemd.AtomRestraint>` and'
            ':class:`GroupRestraint <htmd.mdengine.acemd.acemd.GroupRestraint>`'
            ')'.format(self.__class__.__name__),
            None,
            val.Object(_Restraint),
            nargs='*')

        if self._version == 2:
            self.acemd = Acemd2()
            self.acemd.binindex = None
            self.acemd.binvelocities = None
            self.acemd.bincoordinates = 'output.coor'
            self.acemd.extendedsystem = 'output.xsc'
            self.acemd.coordinates = None
            self.acemd.structure = None
            self.acemd.parameters = None
            self.acemd.temperature = None
            self.acemd.restart = 'on'
            self.acemd.restartfreq = '5000'
            self.acemd.outputname = 'output'
            self.acemd.xtcfile = 'output.xtc'
            self.acemd.xtcfreq = '25000'
            self.acemd.timestep = '4'
            self.acemd.rigidbonds = 'all'
            self.acemd.hydrogenscale = '4'
            self.acemd.switching = 'on'
            self.acemd.switchdist = '7.5'
            self.acemd.cutoff = '9'
            self.acemd.exclude = 'scaled1-4'
            self.acemd.scaling14 = '1.0'
            self.acemd.langevin = 'on'
            self.acemd.langevintemp = None
            self.acemd.langevindamping = '0.1'
            self.acemd.pme = 'on'
            self.acemd.pmegridspacing = '1.0'
            self.acemd.fullelectfrequency = '2'
            self.acemd.energyfreq = '5000'
            self.acemd.consref = None
            self.acemd.run = '$numsteps'
            self.acemd.TCL = ('''
set numsteps {NUMSTEPS}
set fb_refindex {{ {REFINDEX} }}
set fb_selindex {{ {SELINDEX} }}
set fb_box {{ {BOX} }}
set fb_K {KCONST}
#
''', '''
proc flatbot1d {x xm xM fb_K} {
  set f 0
  if {$x < $xm} {
    set f [expr $fb_K*[expr $xm-$x]]
  }
  if {$x > $xM} {
    set f [expr $fb_K*[expr $xM-$x]]
  }
  return $f
}
proc calcforces_init {} {
  global ref sel fb_refindex fb_selindex
  berendsenpressure  off
  set ref [addgroup  $fb_refindex]
  set sel [addgroup  $fb_selindex]
}
proc calcforces {} {
  global ref sel fb_K fb_box
  loadcoords coords
##FLATBOTTOM
  if {$fb_K>0} {
    set r0 $coords($ref)
    set r1 $coords($sel)
    set dr  [vecsub $r1 $r0]
    set fx [flatbot1d [lindex $dr 0] [lindex $fb_box 0] [lindex $fb_box 1] $fb_K]
    set fy [flatbot1d [lindex $dr 1] [lindex $fb_box 2] [lindex $fb_box 3] $fb_K]
    set fz [flatbot1d [lindex $dr 2] [lindex $fb_box 4] [lindex $fb_box 5] $fb_K]
    #print "dr: $dr  fx: $fx fy: $fy fz: $fz"
    addforce $sel [list $fx $fy $fz]
  }
}
proc calcforces_endstep { } { }
''')
        elif self._version == 3:
            self.acemd = Acemd()
            self.acemd.binvelocities = None
            self.acemd.bincoordinates = 'output.coor'
            self.acemd.extendedsystem = 'output.xsc'
            self.acemd.coordinates = None
            self.acemd.structure = None
            self.acemd.parameters = None
            self.acemd.restart = 'on'
            self.acemd.trajectoryfile = 'output.xtc'
            self.acemd.trajectoryfreq = 25000
            self.acemd.timestep = 4
            self.acemd.switching = 'on'
            self.acemd.switchdist = 7.5
            self.acemd.cutoff = 9
            self.acemd.thermostat = 'on'
            self.acemd.thermostatdamping = 0.1
            self.acemd.pme = 'on'
        else:
            raise ValueError(
                '_version can not be {}. Choose either 2 or 3.'.format(
                    self._version))
Beispiel #3
0
class Production(ProtocolInterface):
    """ Production protocol v6

        Production protocol for globular and membrane proteins. You can optionally define a flatbottom potential box and
        atom constraints for the production run.

        An Acemd class object is stored in the Production object which can be used to modify futher options.
        For documentation on further options see :class:`Acemd <htmd.mdengine.acemd.acemd.Acemd>`

        Parameters
        ----------
        runtime : float, default=0
            Running time of the simulation.
        timeunits : str, default='steps'
            Units for runtime. Can be 'steps', 'ns' etc.
        temperature : float, default=300
            Temperature of the thermostat in Kelvin
        fb_k : float, default=0
            Force constant of the flatbottom potential in kcal/mol/A^2. E.g. 5
        fb_reference : str, default='none'
            Reference selection to use as dynamic center of the flatbottom box.
        fb_selection : str, default='none'
            Selection of atoms to apply the flatbottom potential
        fb_box : list, default=[0, 0, 0, 0, 0, 0]
            Position of the flatbottom box in term of the reference center given as [xmin, xmax, ymin, ymax, zmin, zmax]
        useconstantratio : bool, default=False
            For membrane protein simulations set it to true so that the barostat does not modify the xy aspect ratio.
        useconstraints : bool, default=False
            Apply constraints to the production simulation, defined by the constraints parameter
        constraints : dict, default={}
            A dictionary of atomselections and values of the constraint to be applied (in kcal/mol/A^2). Atomselects must be mutually exclusive.
        adaptive : bool, default=False
            Set to True if making production runs for adaptive sampling.
    """
    def __init__(self, _version=2):
        super().__init__()
        self._version = _version
        self._arg('acemd', ':class:`Acemd2 <htmd.apps.acemd.Acemd>` or :class:`Acemd <htmd.mdengine.acemd.acemd.Acemd>`'
                           ' object', 'Acemd class object', None, val.Object([Acemd2, Acemd]))
        self._arg('runtime', 'float', 'Running time of the simulation.', 25000, val.Number(float, '0POS'))
        self._arg('timeunits', 'str', 'Units for runtime. Can be \'steps\', \'ns\' etc.', 'steps', val.String())
        self._arg('temperature', 'float', 'Temperature of the thermostat in Kelvin', 300, val.Number(float, 'ANY'))
        self._arg('fb_k', 'float', 'Force constant of the flatbottom potential in kcal/mol/A^2. E.g. 5', 0,
                  val.Number(float, 'ANY'))
        self._arg('fb_reference', 'str', 'Reference selection to use as dynamic center of the flatbottom box.',
                  'none', val.String())
        self._arg('fb_selection', 'str', 'Selection of atoms to apply the flatbottom potential', 'none', val.String())
        self._arg('fb_box', 'list', 'Position of the flatbottom box in term of the reference center given as '
                                    '[xmin, xmax, ymin, ymax, zmin, zmax]',
                  [0, 0, 0, 0, 0, 0], val.Number(float, 'ANY'), nargs=6)
        self._arg('useconstantratio', 'bool', 'For membrane protein simulations set it to true so that the barostat '
                                              'does not modify the xy aspect ratio.', False, val.Boolean())
        self._arg('useconstraints', 'bool', 'Apply constraints to the production simulation, defined by the '
                                            'constraints parameter', False, val.Boolean())
        self._arg('constraints', 'dict', 'A dictionary of atomselections and values of the constraint to be '
                                         'applied (in kcal/mol/A^2). Atomselects must be mutually exclusive.', {},
                  val.Dictionary(key_type=str))
        self._arg('adaptive', 'bool', 'Set to True if making production runs for adaptive sampling.', False,
                  val.Boolean())
        self._arg('restraints', 'list', 'A list of restraint objects. Only works with {}(_version=3),'
                                'see :class:`AtomRestraint <htmd.mdengine.acemd.acemd.AtomRestraint>` and'
                                ':class:`GroupRestraint <htmd.mdengine.acemd.acemd.GroupRestraint>`'
                                ')'.format(self.__class__.__name__), None, val.Object(_Restraint), nargs='*')

        if self._version == 2:
            self.acemd = Acemd2()
            self.acemd.binindex = None
            self.acemd.binvelocities = None
            self.acemd.bincoordinates = 'output.coor'
            self.acemd.extendedsystem = 'output.xsc'
            self.acemd.coordinates = None
            self.acemd.structure = None
            self.acemd.parameters = None
            self.acemd.temperature = None
            self.acemd.restart = 'on'
            self.acemd.restartfreq = '5000'
            self.acemd.outputname = 'output'
            self.acemd.xtcfile = 'output.xtc'
            self.acemd.xtcfreq = '25000'
            self.acemd.timestep = '4'
            self.acemd.rigidbonds = 'all'
            self.acemd.hydrogenscale = '4'
            self.acemd.switching = 'on'
            self.acemd.switchdist = '7.5'
            self.acemd.cutoff = '9'
            self.acemd.exclude = 'scaled1-4'
            self.acemd.scaling14 = '1.0'
            self.acemd.langevin = 'on'
            self.acemd.langevintemp = None
            self.acemd.langevindamping = '0.1'
            self.acemd.pme = 'on'
            self.acemd.pmegridspacing = '1.0'
            self.acemd.fullelectfrequency = '2'
            self.acemd.energyfreq = '5000'
            self.acemd.consref = None
            self.acemd.run = '$numsteps'
            self.acemd.TCL = ('''
set numsteps {NUMSTEPS}
set fb_refindex {{ {REFINDEX} }}
set fb_selindex {{ {SELINDEX} }}
set fb_box {{ {BOX} }}
set fb_K {KCONST}
#
''',
'''
proc flatbot1d {x xm xM fb_K} {
  set f 0
  if {$x < $xm} {
    set f [expr $fb_K*[expr $xm-$x]]
  }
  if {$x > $xM} {
    set f [expr $fb_K*[expr $xM-$x]]
  }
  return $f
}
proc calcforces_init {} {
  global ref sel fb_refindex fb_selindex
  berendsenpressure  off
  set ref [addgroup  $fb_refindex]
  set sel [addgroup  $fb_selindex]
}
proc calcforces {} {
  global ref sel fb_K fb_box
  loadcoords coords
##FLATBOTTOM
  if {$fb_K>0} {
    set r0 $coords($ref)
    set r1 $coords($sel)
    set dr  [vecsub $r1 $r0]
    set fx [flatbot1d [lindex $dr 0] [lindex $fb_box 0] [lindex $fb_box 1] $fb_K]
    set fy [flatbot1d [lindex $dr 1] [lindex $fb_box 2] [lindex $fb_box 3] $fb_K]
    set fz [flatbot1d [lindex $dr 2] [lindex $fb_box 4] [lindex $fb_box 5] $fb_K]
    #print "dr: $dr  fx: $fx fy: $fy fz: $fz"
    addforce $sel [list $fx $fy $fz]
  }
}
proc calcforces_endstep { } { }
''')
        elif self._version == 3:
            self.acemd = Acemd()
            self.acemd.binvelocities = None
            self.acemd.bincoordinates = 'output.coor'
            self.acemd.extendedsystem = 'output.xsc'
            self.acemd.coordinates = None
            self.acemd.structure = None
            self.acemd.parameters = None
            self.acemd.restart = 'on'
            self.acemd.trajectoryfile = 'output.xtc'
            self.acemd.trajectoryfreq = 25000
            self.acemd.timestep = 4
            self.acemd.switching = 'on'
            self.acemd.switchdist = 7.5
            self.acemd.cutoff = 9
            self.acemd.thermostat = 'on'
            self.acemd.thermostatdamping = 0.1
            self.acemd.pme = 'on'
        else:
            raise ValueError('_version can not be {}. Choose either 2 or 3.'.format(self._version))

    def _findFiles(self, inputdir):
        # Tries to find default files if the given don't exist
        defaults = {'coordinates': ('structure.pdb',),
                    'structure': ('structure.psf', 'structure.prmtop'),
                    'parameters': ('parameters', 'structure.prmtop')}

        for field in defaults:
            userval = self.acemd.__dict__[field]
            if userval is not None and not os.path.exists(os.path.join(inputdir, userval)):
                raise RuntimeError('Could not locate file {} set by the user for argument '
                                   'Production.acemd.{}'.format(os.path.join(inputdir, userval), field))

            if self.acemd.__dict__[field] is None:
                for val in defaults[field]:
                    if os.path.exists(os.path.join(inputdir, val)):
                        self.acemd.__dict__[field] = val
                        break

            if userval is not None and self.acemd.__dict__[field] is not None and self.acemd.__dict__[field] != userval:
                logger.warning('Could not locate structure file {}. Using {} instead.'.format(
                    os.path.join(inputdir, userval), os.path.join(inputdir, self.acemd.__dict__[field])
                ))
            elif self.acemd.__dict__[field] is None:
                raise RuntimeError('Could not locate any {f:} file in {i:}. '
                                   'Please set the Production.acemd.{f:} property to '
                                   'point to the {f:} file'.format(f=field, i=inputdir))

            if self._version == 2:
                if self.useconstraints and self.acemd.consref is None:
                    self.acemd.consref = self.acemd.coordinates

    def _amberFixes(self):
        # AMBER specific fixes
        if self.acemd.structure.endswith('.prmtop'):
            self.acemd.parmfile = self.acemd.parameters
            self.acemd.parameters = None
            if self._version == 2:
                self.acemd.scaling14 = '0.8333333'
                self.acemd.amber = 'on'

    def _fb_potential2restraints(self, inputdir):
        from htmd.molecule.molecule import Molecule
        restraints = list()

        fb_box = np.array(self.fb_box)
        # convert fb_box to width
        width = list(np.concatenate(np.diff(np.array([fb_box[::2], fb_box[1::2]]), axis=0)))

        # If fb_box is not symmetrical
        if not np.all(fb_box[::2] == -fb_box[1::2]):
            # convert fb_box and fb_reference to fbcentre and width
            mol = Molecule(os.path.join(inputdir, self.acemd.structure))
            mol.read(os.path.join(inputdir, self.acemd.coordinates))
            fb_refcentre = mol.get('coords', sel=self.fb_reference).mean(axis=0).squeeze()

            fbcentre = list(np.around(np.mean(np.array([fb_box[::2], fb_box[1::2]]), axis=0) + fb_refcentre, 3))
            restraints.append(GroupRestraint(self.fb_selection, width, [(self.fb_k, 0)], fbcentre=fbcentre))
        else:
            restraints.append(GroupRestraint(self.fb_selection, width, [(self.fb_k, 0)], fbcentresel=self.fb_reference))

        return restraints

    def _constraints2restraints(self):

        restraints = list()
        for constr in sorted(self.constraints):
            restraints.append(AtomRestraint(constr, 0, [(self.constraints[constr], 0)]))

        return restraints

    def write(self, inputdir, outputdir):
        """ Writes the production protocol and files into a folder.

        Parameters
        ----------
        inputdir : str
            Path to a directory containing the files produced by a equilibration process.
        outputdir : str
            Directory where to write the production setup files.
        """
        from htmd.molecule.molecule import Molecule

        # Do version consistency check
        if (self._version == 2 and not isinstance(self.acemd, Acemd2)) and \
                (self._version == 3 and not isinstance(self.acemd, Acemd)):
            raise RuntimeError('Acemd object version ({}) inconsistent with protocol version at instantiation '
                               '({})'.format(type(self.acemd), self._version))

        self._findFiles(inputdir)
        self._amberFixes()

        if self._version == 2:
            self.acemd.temperature = str(self.temperature)
            self.acemd.langevintemp = str(self.temperature)
        elif self._version == 3:
            self.acemd.temperature = self.temperature
            self.acemd.thermostattemp = self.temperature

        from htmd.units import convert
        numsteps = convert(self.timeunits, 'timesteps', self.runtime, timestep=self.acemd.timestep)
        if self._version == 3:
            self.acemd.run = str(numsteps)

        pdbfile = os.path.join(inputdir, self.acemd.coordinates)
        inmol = Molecule(pdbfile)

        if np.any(inmol.atomselect('lipids')) and not self.useconstantratio:
            logger.warning('Lipids detected in input structure. We highly recommend setting useconstantratio=True '
                           'for membrane simulations.')

        if self._version == 2:
            if self.restraints:
                raise RuntimeWarning('restraints are only available on {}(_version=3)'.format(self.__class__.__name__))
            if self.fb_k > 0:  # use TCL only for flatbottom
                self.acemd.tclforces = 'on'
                if isinstance(self.acemd.TCL, tuple):
                    tcl = list(self.acemd.TCL)
                    tcl[0] = tcl[0].format(NUMSTEPS=numsteps, TEMPERATURE=self.temperature, KCONST=self.fb_k,
                                           REFINDEX=' '.join(map(str, inmol.get('index', self.fb_reference))),
                                           SELINDEX=' '.join(map(str, inmol.get('index', self.fb_selection))),
                                           BOX=' '.join(map(str, self.fb_box)))
                    self.acemd.TCL = tcl[0] + tcl[1]
                else:
                    logger.warning('{} default TCL was already formatted.'.format(self.__class__.__name__))
            else:
                self.acemd.TCL = 'set numsteps {NUMSTEPS}\n'.format(NUMSTEPS=numsteps)
            if self.useconstraints:
                # Turn on constraints
                self.acemd.constraints = 'on'
                self.acemd.constraintscaling = '1.0'
            else:
                if len(self.constraints) != 0:
                    logger.warning('You have setup constraints to {} but constraints are turned off. '
                                   'If you want to use constraints, define '
                                   'useconstraints=True'.format(self.constraints))
        elif self._version == 3:
            if self.restraints is not None:
                logger.info('Using user-provided restraints and ignoring constraints and fb_potential')
                self.acemd.restraints = self.restraints
            else:
                restraints = list()
                if self.fb_k > 0:
                    logger.warning('Converting fb_potential to restraints. This is a convenience '
                                   'functional conversion. We recommend start using restraints with '
                                   '{}(_version=3)'.format(self.__class__.__name__))
                    restraints += self._fb_potential2restraints(inputdir)
                if self.useconstraints:
                    logger.warning('Converting constraints to restraints. This is a convenience '
                                   'functional conversion. We recommend start using restraints with '
                                   '{}(_version=3)'.format(self.__class__.__name__))
                    restraints += self._constraints2restraints()
                else:
                    if len(self.constraints) != 0:
                        logger.warning('You have setup constraints to {} but constraints are turned off. '
                                       'If you want to use constraints, define '
                                       'useconstraints=True'.format(self.constraints))
                if len(restraints) != 0:
                    self.acemd.restraints = restraints

        if self.useconstantratio:
            self.acemd.useconstantratio = 'on'

        if self.adaptive:
            self.acemd.binvelocities = None

        self.acemd.setup(inputdir, outputdir, overwrite=True)

        if self._version == 2:
            # Adding constraints by writing them to the consref file
            if self.useconstraints:
                inconsreffile = os.path.join(inputdir, self.acemd.consref)
                consrefmol = Molecule(inconsreffile)
                consrefmol.set('occupancy', 0)
                consrefmol.set('beta', 0)
                if len(self.constraints) == 0:
                    raise RuntimeError('You have set the production to use constraints (useconstraints=True), but have '
                                       'not defined any constraints (constraints={}).')
                else:
                    for sel in self.constraints:
                        consrefmol.set('beta', self.constraints[sel], sel)
                outconsreffile = os.path.join(outputdir, self.acemd.consref)
                consrefmol.write(outconsreffile)

    def addConstraint(self, atomselect, factor=1):
        """ Convenience function for adding a new constraint to existing constraints.

        Parameters
        ----------
        atomselect : str
            Atom selection of atoms we want to constrain
        factor : float
            The scaling factor of the constraints applied to the atoms

        Example
        -------
        >>> eq.addConstraint('chain X', 0.3)
        """
        self.constraints[atomselect] = factor
Beispiel #4
0
    def __init__(self, _version=2):
        super().__init__()
        self._version = _version
        self._arg('acemd', ':class:`Acemd2 <htmd.apps.acemd.Acemd>` or :class:`Acemd <htmd.mdengine.acemd.acemd.Acemd>`'
                           ' object', 'Acemd class object', None, val.Object([Acemd2, Acemd]))
        self._arg('runtime', 'float', 'Running time of the simulation.', 25000, val.Number(float, '0POS'))
        self._arg('timeunits', 'str', 'Units for runtime. Can be \'steps\', \'ns\' etc.', 'steps', val.String())
        self._arg('temperature', 'float', 'Temperature of the thermostat in Kelvin', 300, val.Number(float, 'ANY'))
        self._arg('fb_k', 'float', 'Force constant of the flatbottom potential in kcal/mol/A^2. E.g. 5', 0,
                  val.Number(float, 'ANY'))
        self._arg('fb_reference', 'str', 'Reference selection to use as dynamic center of the flatbottom box.',
                  'none', val.String())
        self._arg('fb_selection', 'str', 'Selection of atoms to apply the flatbottom potential', 'none', val.String())
        self._arg('fb_box', 'list', 'Position of the flatbottom box in term of the reference center given as '
                                    '[xmin, xmax, ymin, ymax, zmin, zmax]',
                  [0, 0, 0, 0, 0, 0], val.Number(float, 'ANY'), nargs=6)
        self._arg('useconstantratio', 'bool', 'For membrane protein simulations set it to true so that the barostat '
                                              'does not modify the xy aspect ratio.', False, val.Boolean())
        self._arg('useconstraints', 'bool', 'Apply constraints to the production simulation, defined by the '
                                            'constraints parameter', False, val.Boolean())
        self._arg('constraints', 'dict', 'A dictionary of atomselections and values of the constraint to be '
                                         'applied (in kcal/mol/A^2). Atomselects must be mutually exclusive.', {},
                  val.Dictionary(key_type=str))
        self._arg('adaptive', 'bool', 'Set to True if making production runs for adaptive sampling.', False,
                  val.Boolean())
        self._arg('restraints', 'list', 'A list of restraint objects. Only works with {}(_version=3),'
                                'see :class:`AtomRestraint <htmd.mdengine.acemd.acemd.AtomRestraint>` and'
                                ':class:`GroupRestraint <htmd.mdengine.acemd.acemd.GroupRestraint>`'
                                ')'.format(self.__class__.__name__), None, val.Object(_Restraint), nargs='*')

        if self._version == 2:
            self.acemd = Acemd2()
            self.acemd.binindex = None
            self.acemd.binvelocities = None
            self.acemd.bincoordinates = 'output.coor'
            self.acemd.extendedsystem = 'output.xsc'
            self.acemd.coordinates = None
            self.acemd.structure = None
            self.acemd.parameters = None
            self.acemd.temperature = None
            self.acemd.restart = 'on'
            self.acemd.restartfreq = '5000'
            self.acemd.outputname = 'output'
            self.acemd.xtcfile = 'output.xtc'
            self.acemd.xtcfreq = '25000'
            self.acemd.timestep = '4'
            self.acemd.rigidbonds = 'all'
            self.acemd.hydrogenscale = '4'
            self.acemd.switching = 'on'
            self.acemd.switchdist = '7.5'
            self.acemd.cutoff = '9'
            self.acemd.exclude = 'scaled1-4'
            self.acemd.scaling14 = '1.0'
            self.acemd.langevin = 'on'
            self.acemd.langevintemp = None
            self.acemd.langevindamping = '0.1'
            self.acemd.pme = 'on'
            self.acemd.pmegridspacing = '1.0'
            self.acemd.fullelectfrequency = '2'
            self.acemd.energyfreq = '5000'
            self.acemd.consref = None
            self.acemd.run = '$numsteps'
            self.acemd.TCL = ('''
set numsteps {NUMSTEPS}
set fb_refindex {{ {REFINDEX} }}
set fb_selindex {{ {SELINDEX} }}
set fb_box {{ {BOX} }}
set fb_K {KCONST}
#
''',
'''
proc flatbot1d {x xm xM fb_K} {
  set f 0
  if {$x < $xm} {
    set f [expr $fb_K*[expr $xm-$x]]
  }
  if {$x > $xM} {
    set f [expr $fb_K*[expr $xM-$x]]
  }
  return $f
}
proc calcforces_init {} {
  global ref sel fb_refindex fb_selindex
  berendsenpressure  off
  set ref [addgroup  $fb_refindex]
  set sel [addgroup  $fb_selindex]
}
proc calcforces {} {
  global ref sel fb_K fb_box
  loadcoords coords
##FLATBOTTOM
  if {$fb_K>0} {
    set r0 $coords($ref)
    set r1 $coords($sel)
    set dr  [vecsub $r1 $r0]
    set fx [flatbot1d [lindex $dr 0] [lindex $fb_box 0] [lindex $fb_box 1] $fb_K]
    set fy [flatbot1d [lindex $dr 1] [lindex $fb_box 2] [lindex $fb_box 3] $fb_K]
    set fz [flatbot1d [lindex $dr 2] [lindex $fb_box 4] [lindex $fb_box 5] $fb_K]
    #print "dr: $dr  fx: $fx fy: $fy fz: $fz"
    addforce $sel [list $fx $fy $fz]
  }
}
proc calcforces_endstep { } { }
''')
        elif self._version == 3:
            self.acemd = Acemd()
            self.acemd.binvelocities = None
            self.acemd.bincoordinates = 'output.coor'
            self.acemd.extendedsystem = 'output.xsc'
            self.acemd.coordinates = None
            self.acemd.structure = None
            self.acemd.parameters = None
            self.acemd.restart = 'on'
            self.acemd.trajectoryfile = 'output.xtc'
            self.acemd.trajectoryfreq = 25000
            self.acemd.timestep = 4
            self.acemd.switching = 'on'
            self.acemd.switchdist = 7.5
            self.acemd.cutoff = 9
            self.acemd.thermostat = 'on'
            self.acemd.thermostatdamping = 0.1
            self.acemd.pme = 'on'
        else:
            raise ValueError('_version can not be {}. Choose either 2 or 3.'.format(self._version))
Beispiel #5
0
    def __init__(self, _version=_config["acemdversion"]):
        if _version == 2:
            raise RuntimeError("Equilibration v3 only supports _version=3")

        super().__init__()
        self._arg(
            "acemd",
            ":class:`Acemd <htmd.mdengine.acemd.acemd.Acemd>` object",
            "Acemd class object",
            None,
            val.Object([Acemd2, Acemd]),
        )
        self._arg(
            "runtime",
            "float",
            "Running time of the simulation.",
            25000,
            val.Number(float, "0POS"),
        )
        self._arg(
            "timeunits",
            "str",
            "Units for time arguments. Can be 'steps', 'ns' etc.",
            "steps",
            val.String(),
        )
        self._arg(
            "temperature",
            "float",
            "Temperature of the thermostat in Kelvin",
            300,
            val.Number(float, "ANY"),
        )
        self._arg(
            "useconstantratio",
            "bool",
            "For membrane protein simulations set it to true so that the barostat "
            "does not modify the xy aspect ratio.",
            False,
            val.Boolean(),
        )
        self._arg(
            "restraintsteps",
            "int",
            "Number of initial steps to apply restraints in units of 4fs. Defaults "
            "to half the simulation time.",
            None,
            val.Number(int, "ANY"),
        )
        self._arg(
            "restraints",
            "list",
            "A list of restraint objects. If None will apply defaultEquilRestraints decaying over half the runtime. If no restraints are required set to empty list []."
            "See :class:`AtomRestraint <htmd.mdengine.acemd.acemd.AtomRestraint>` and"
            ":class:`GroupRestraint <htmd.mdengine.acemd.acemd.GroupRestraint>`)",
            None,
            val.Object(_Restraint),
            nargs="*",
        )

        self.acemd = Acemd()
        self.acemd.coordinates = None
        self.acemd.structure = None
        self.acemd.parameters = None
        self.acemd.restart = "on"
        self.acemd.trajectoryfile = "output.xtc"
        self.acemd.trajectoryperiod = 25000
        self.acemd.timestep = 4
        self.acemd.switching = "on"
        self.acemd.switchdistance = 7.5
        self.acemd.cutoff = 9
        self.acemd.thermostat = "on"
        self.acemd.thermostatdamping = 1
        self.acemd.pme = "on"
        self.acemd.barostat = "on"
        self.acemd.barostatpressure = 1.01325
        self.acemd.minimize = 500
Beispiel #6
0
class Equilibration(ProtocolInterface):
    """Equilibration protocol v3

    Equilibration protocol for globular and membrane proteins
    Supporst extra restraints like a flatbottom potential box to retain a ligand
    for example within this box.

    Parameters
    ----------
    runtime : float, default=0
        Running time of the simulation.
    timeunits : str, default='steps'
        Units for time arguments. Can be 'steps', 'ns' etc.
    temperature : float, default=300
        Temperature of the thermostat in Kelvin
    restraints : list, default=None
        A list of restraint objects. See :class:`AtomRestraint <htmd.mdengine.acemd.acemd.AtomRestraint>` and:class:`GroupRestraint<htmd.mdengine.acemd.acemd.GroupRestraint>`)
    useconstantratio : bool, default=False
        For membrane protein simulations set it to true so that the barostat does not modify the xy aspect ratio.
    restraintsteps : int, default=None
        Number of initial steps to apply restraints in units of 4fs. Defaults to half the simulation time.

    Example
    -------
    >>> from htmd.protocols.equilibration_v3 import Equilibration
    >>> from htmd.mdengine.acemd.acemd import GroupRestraint
    >>> md = Equilibration()
    >>> md.runtime = 4
    >>> md.timeunits = 'ns'
    >>> md.temperature = 300
    >>> md.useconstantratio = True  # only for membrane sims
    Use a 10A flat bottom potential to prevent the ligand from diffusing from original position during equilibration
    >>> width = np.array([10, 10, 10])
    >>> flatbot = GroupRestraint('segname L and noh', width, [(5, '0ns')])
    Add also the default restraints for protein
    >>> mol = Molecule("./build/structure.pdb")
    >>> md.restraints = [flatbot,] + md.defaultEquilRestraints('2ns', mol)
    >>> md.write('./build','./equil')
    """
    def __init__(self, _version=_config["acemdversion"]):
        if _version == 2:
            raise RuntimeError("Equilibration v3 only supports _version=3")

        super().__init__()
        self._arg(
            "acemd",
            ":class:`Acemd <htmd.mdengine.acemd.acemd.Acemd>` object",
            "Acemd class object",
            None,
            val.Object([Acemd2, Acemd]),
        )
        self._arg(
            "runtime",
            "float",
            "Running time of the simulation.",
            25000,
            val.Number(float, "0POS"),
        )
        self._arg(
            "timeunits",
            "str",
            "Units for time arguments. Can be 'steps', 'ns' etc.",
            "steps",
            val.String(),
        )
        self._arg(
            "temperature",
            "float",
            "Temperature of the thermostat in Kelvin",
            300,
            val.Number(float, "ANY"),
        )
        self._arg(
            "useconstantratio",
            "bool",
            "For membrane protein simulations set it to true so that the barostat "
            "does not modify the xy aspect ratio.",
            False,
            val.Boolean(),
        )
        self._arg(
            "restraintsteps",
            "int",
            "Number of initial steps to apply restraints in units of 4fs. Defaults "
            "to half the simulation time.",
            None,
            val.Number(int, "ANY"),
        )
        self._arg(
            "restraints",
            "list",
            "A list of restraint objects. If None will apply defaultEquilRestraints decaying over half the runtime. If no restraints are required set to empty list []."
            "See :class:`AtomRestraint <htmd.mdengine.acemd.acemd.AtomRestraint>` and"
            ":class:`GroupRestraint <htmd.mdengine.acemd.acemd.GroupRestraint>`)",
            None,
            val.Object(_Restraint),
            nargs="*",
        )

        self.acemd = Acemd()
        self.acemd.coordinates = None
        self.acemd.structure = None
        self.acemd.parameters = None
        self.acemd.restart = "on"
        self.acemd.trajectoryfile = "output.xtc"
        self.acemd.trajectoryperiod = 25000
        self.acemd.timestep = 4
        self.acemd.switching = "on"
        self.acemd.switchdistance = 7.5
        self.acemd.cutoff = 9
        self.acemd.thermostat = "on"
        self.acemd.thermostatdamping = 1
        self.acemd.pme = "on"
        self.acemd.barostat = "on"
        self.acemd.barostatpressure = 1.01325
        self.acemd.minimize = 500

    def _findFiles(self, inputdir):
        # Tries to find default files if the given don't exist
        defaults = {
            "coordinates": ("structure.pdb", ),
            "structure": ("structure.psf", "structure.prmtop"),
            "parameters": ("parameters", "structure.prmtop"),
        }

        for field in defaults:
            userval = self.acemd.__dict__[field]
            if userval is not None and not os.path.exists(
                    os.path.join(inputdir, userval)):
                self.acemd.__dict__[field] = None

            if self.acemd.__dict__[field] is None:
                for val in defaults[field]:
                    if os.path.exists(os.path.join(inputdir, val)):
                        self.acemd.__dict__[field] = val
                        break

            if (userval is not None and self.acemd.__dict__[field] is not None
                    and self.acemd.__dict__[field] != userval):
                logger.warning(
                    "Could not locate structure file {}. Using {} instead.".
                    format(
                        os.path.join(inputdir, userval),
                        os.path.join(inputdir, self.acemd.__dict__[field]),
                    ))
            elif self.acemd.__dict__[field] is None:
                raise RuntimeError(
                    "Could not locate any {f:} file in {i:}. "
                    "Please set the {name:}.acemd.{f:} property to "
                    "point to the {f:} file".format(
                        f=field, i=inputdir, name=self.__class__.__name__))

    def _amberFixes(self):
        # AMBER specific fixes
        if self.acemd.parameters.endswith("structure.prmtop"):
            self.acemd.parmfile = self.acemd.parameters
            self.acemd.parameters = None

    def defaultEquilRestraints(self, decay, mol=None):
        """Get the default equilibration restraints

        Parameters
        ----------
        decay : str
            The restrains will get scaled to 0 over this much time.

        Returns
        -------
        restraints : list
            A list of default protein restraints

        Examples
        --------
        >>> md = Equilibration()
        >>> res = md.defaultEquilRestraints('20ns')
        """
        caatoms = AtomRestraint("protein and name CA", 0, [(1, 0), (0, decay)])
        notcaatoms = AtomRestraint("protein and noh and not name CA", 0,
                                   [(0.1, 0), (0, decay)])
        nucleic = AtomRestraint("nucleic and backbone", 0, [(1, 0),
                                                            (0, decay)])
        nucleicside = AtomRestraint("nucleic and not backbone and noh", 0,
                                    [(0.1, 0), (0, decay)])
        restraints = [caatoms, notcaatoms, nucleic, nucleicside]
        if mol is not None:
            restraints = [
                r for r in restraints if mol.atomselect(r.selection).sum()
            ]

        return restraints

    def write(self, inputdir, outputdir):
        """Write the equilibration protocol

        Writes the equilibration protocol and files into a folder for execution
        using files inside the inputdir directory

        Parameters
        ----------
        inputdir : str
            Path to a directory containing the files produced by a build process.
        outputdir : str
            Directory where to write the equilibration setup files.

        Examples
        --------
        >>> md = Equilibration()
        >>> md.write('./build','./equil')
        """

        from moleculekit.molecule import Molecule

        self._findFiles(inputdir)
        self._amberFixes()

        from htmd.units import convert

        numsteps = convert(self.timeunits,
                           "timesteps",
                           self.runtime,
                           timestep=self.acemd.timestep)

        self.acemd.temperature = self.temperature
        self.acemd.thermostattemperature = self.temperature
        self.acemd.run = str(numsteps)

        pdbfile = os.path.join(inputdir, self.acemd.coordinates)
        inmol = Molecule(pdbfile)

        from htmd.builder.builder import detectCisPeptideBonds

        detectCisPeptideBonds(inmol)

        if np.any(inmol.atomselect("lipids")) and not self.useconstantratio:
            logger.warning(
                "Lipids detected in input structure. We highly recommend setting useconstantratio=True "
                "for membrane simulations.")

        if self.restraintsteps is None:
            constrsteps = int(numsteps / 2)
        else:
            constrsteps = int(self.restraintsteps)

        if self.restraints is not None:
            self.acemd.restraints = self.restraints
        else:
            self.acemd.restraints = self.defaultEquilRestraints(constrsteps,
                                                                mol=inmol)

        if self.acemd.boxsize is None and self.acemd.extendedsystem is None:
            coords = inmol.get("coords", sel="water")
            if coords.size == 0:  # It's a vacuum simulation
                coords = inmol.get("coords", sel="all")
                dim = np.max(coords, axis=0) - np.min(coords, axis=0)
                dim += 12.0
            else:
                dim = np.max(coords, axis=0) - np.min(coords, axis=0)
            self.acemd.boxsize = "{} {} {}".format(dim[0], dim[1], dim[2])

        if self.useconstantratio:
            self.acemd.useconstantratio = "on"

        self.acemd.setup(inputdir, outputdir, overwrite=True)
Beispiel #7
0
    def __init__(self):
        super().__init__()
        self._arg(
            "acemd",
            ":class:`Acemd <htmd.mdengine.acemd.acemd.Acemd>`"
            " object",
            "Acemd class object",
            None,
            val.Object(Acemd),
        )
        self._arg(
            "runtime",
            "float",
            "Running time of the simulation.",
            25000,
            val.Number(float, "0POS"),
        )
        self._arg(
            "timeunits",
            "str",
            "Units for runtime. Can be 'steps', 'ns' etc.",
            "steps",
            val.String(),
        )
        self._arg(
            "temperature",
            "float",
            "Temperature of the thermostat in Kelvin",
            300,
            val.Number(float, "ANY"),
        )
        self._arg(
            "fb_k",
            "float",
            "Force constant of the flatbottom potential in kcal/mol/A^2. E.g. 5",
            0,
            val.Number(float, "ANY"),
        )
        self._arg(
            "fb_reference",
            "str",
            "Reference selection to use as dynamic center of the flatbottom box.",
            "none",
            val.String(),
        )
        self._arg(
            "fb_selection",
            "str",
            "Selection of atoms to apply the flatbottom potential",
            "none",
            val.String(),
        )
        self._arg(
            "fb_box",
            "list",
            "Position of the flatbottom box in term of the reference center given as "
            "[xmin, xmax, ymin, ymax, zmin, zmax]",
            [0, 0, 0, 0, 0, 0],
            val.Number(float, "ANY"),
            nargs=6,
        )
        self._arg(
            "useconstantratio",
            "bool",
            "For membrane protein simulations set it to true so that the barostat "
            "does not modify the xy aspect ratio.",
            False,
            val.Boolean(),
        )
        self._arg(
            "useconstraints",
            "bool",
            "Apply constraints to the production simulation, defined by the "
            "constraints parameter",
            False,
            val.Boolean(),
        )
        self._arg(
            "constraints",
            "dict",
            "A dictionary of atomselections and values of the constraint to be "
            "applied (in kcal/mol/A^2). Atomselects must be mutually exclusive.",
            {},
            val.Dictionary(key_type=str),
        )
        self._arg(
            "adaptive",
            "bool",
            "Set to True if making production runs for adaptive sampling.",
            False,
            val.Boolean(),
        )
        self._arg(
            "restraints",
            "list",
            "A list of restraint objects."
            "See :class:`AtomRestraint <htmd.mdengine.acemd.acemd.AtomRestraint>` and"
            ":class:`GroupRestraint <htmd.mdengine.acemd.acemd.GroupRestraint>`"
            ")",
            None,
            val.Object(_Restraint),
            nargs="*",
        )

        self.acemd = Acemd()
        self.acemd.binvelocities = None
        self.acemd.bincoordinates = "output.coor"
        self.acemd.extendedsystem = "output.xsc"
        self.acemd.coordinates = None
        self.acemd.structure = None
        self.acemd.parameters = None
        self.acemd.restart = "on"
        self.acemd.trajectoryfile = "output.xtc"
        self.acemd.trajectoryperiod = 25000
        self.acemd.timestep = 4
        self.acemd.switching = "on"
        self.acemd.switchdistance = 7.5
        self.acemd.cutoff = 9
        self.acemd.thermostat = "on"
        self.acemd.thermostatdamping = 0.1
        self.acemd.pme = "on"
Beispiel #8
0
class Production(ProtocolInterface):
    """Production protocol v6

    Production protocol for globular and membrane proteins. You can optionally define a flatbottom potential box and
    atom constraints for the production run.

    An Acemd class object is stored in the Production object which can be used to modify futher options.
    For documentation on further options see :class:`Acemd <htmd.mdengine.acemd.acemd.Acemd>`

    Parameters
    ----------
    runtime : float, default=0
        Running time of the simulation.
    timeunits : str, default='steps'
        Units for runtime. Can be 'steps', 'ns' etc.
    temperature : float, default=300
        Temperature of the thermostat in Kelvin
    useconstantratio : bool, default=False
        For membrane protein simulations set it to true so that the barostat does not modify the xy aspect ratio.
    restraints : list, default=None
        A list of restraint objects. See :class:`AtomRestraint <htmd.mdengine.acemd.acemd.AtomRestraint>` and :class:`GroupRestraint<htmd.mdengine.acemd.acemd.GroupRestraint>`)
    adaptive : bool, default=False
        Set to True if making production runs for adaptive sampling.

    Example
    -------
    >>> from htmd.protocols.production_v6 import Production
    >>> from htmd.mdengine.acemd.acemd import GroupRestraint
    >>> md = Production()
    >>> md.runtime = 4
    >>> md.timeunits = 'ns'
    >>> md.temperature = 300
    >>> md.useconstantratio = True  # only for membrane sims
    Use a 10x10x30A flat bottom potential centered on protein residue 142 to prevent the ligand from crossing periodic boxes
    ending up on the other side of the membrane.
    >>> width = [10, 10, 30]
    >>> flatbot = GroupRestraint('segname L and noh', width, [(5, '0ns')], fbcentersel="protein and resid 142")
    >>> md.restraints = flatbot
    >>> md.write('./build','./equil')
    """
    def __init__(self):
        super().__init__()
        self._arg(
            "acemd",
            ":class:`Acemd <htmd.mdengine.acemd.acemd.Acemd>`"
            " object",
            "Acemd class object",
            None,
            val.Object(Acemd),
        )
        self._arg(
            "runtime",
            "float",
            "Running time of the simulation.",
            25000,
            val.Number(float, "0POS"),
        )
        self._arg(
            "timeunits",
            "str",
            "Units for runtime. Can be 'steps', 'ns' etc.",
            "steps",
            val.String(),
        )
        self._arg(
            "temperature",
            "float",
            "Temperature of the thermostat in Kelvin",
            300,
            val.Number(float, "ANY"),
        )
        self._arg(
            "fb_k",
            "float",
            "Force constant of the flatbottom potential in kcal/mol/A^2. E.g. 5",
            0,
            val.Number(float, "ANY"),
        )
        self._arg(
            "fb_reference",
            "str",
            "Reference selection to use as dynamic center of the flatbottom box.",
            "none",
            val.String(),
        )
        self._arg(
            "fb_selection",
            "str",
            "Selection of atoms to apply the flatbottom potential",
            "none",
            val.String(),
        )
        self._arg(
            "fb_box",
            "list",
            "Position of the flatbottom box in term of the reference center given as "
            "[xmin, xmax, ymin, ymax, zmin, zmax]",
            [0, 0, 0, 0, 0, 0],
            val.Number(float, "ANY"),
            nargs=6,
        )
        self._arg(
            "useconstantratio",
            "bool",
            "For membrane protein simulations set it to true so that the barostat "
            "does not modify the xy aspect ratio.",
            False,
            val.Boolean(),
        )
        self._arg(
            "useconstraints",
            "bool",
            "Apply constraints to the production simulation, defined by the "
            "constraints parameter",
            False,
            val.Boolean(),
        )
        self._arg(
            "constraints",
            "dict",
            "A dictionary of atomselections and values of the constraint to be "
            "applied (in kcal/mol/A^2). Atomselects must be mutually exclusive.",
            {},
            val.Dictionary(key_type=str),
        )
        self._arg(
            "adaptive",
            "bool",
            "Set to True if making production runs for adaptive sampling.",
            False,
            val.Boolean(),
        )
        self._arg(
            "restraints",
            "list",
            "A list of restraint objects."
            "See :class:`AtomRestraint <htmd.mdengine.acemd.acemd.AtomRestraint>` and"
            ":class:`GroupRestraint <htmd.mdengine.acemd.acemd.GroupRestraint>`"
            ")",
            None,
            val.Object(_Restraint),
            nargs="*",
        )

        self.acemd = Acemd()
        self.acemd.binvelocities = None
        self.acemd.bincoordinates = "output.coor"
        self.acemd.extendedsystem = "output.xsc"
        self.acemd.coordinates = None
        self.acemd.structure = None
        self.acemd.parameters = None
        self.acemd.restart = "on"
        self.acemd.trajectoryfile = "output.xtc"
        self.acemd.trajectoryperiod = 25000
        self.acemd.timestep = 4
        self.acemd.switching = "on"
        self.acemd.switchdistance = 7.5
        self.acemd.cutoff = 9
        self.acemd.thermostat = "on"
        self.acemd.thermostatdamping = 0.1
        self.acemd.pme = "on"

    def _findFiles(self, inputdir):
        # Tries to find default files if the given don't exist
        defaults = {
            "coordinates": ("structure.pdb", ),
            "structure": ("structure.psf", "structure.prmtop"),
            "parameters": ("parameters", "structure.prmtop"),
        }

        for field in defaults:
            userval = self.acemd.__dict__[field]
            if userval is not None and not os.path.exists(
                    os.path.join(inputdir, userval)):
                raise RuntimeError(
                    "Could not locate file {} set by the user for argument "
                    "Production.acemd.{}".format(
                        os.path.join(inputdir, userval), field))

            if self.acemd.__dict__[field] is None:
                for vv in defaults[field]:
                    if os.path.exists(os.path.join(inputdir, vv)):
                        self.acemd.__dict__[field] = vv
                        break

            if (userval is not None and self.acemd.__dict__[field] is not None
                    and self.acemd.__dict__[field] != userval):
                logger.warning(
                    "Could not locate structure file {}. Using {} instead.".
                    format(
                        os.path.join(inputdir, userval),
                        os.path.join(inputdir, self.acemd.__dict__[field]),
                    ))
            elif self.acemd.__dict__[field] is None:
                raise RuntimeError(
                    "Could not locate any {f:} file in {i:}. "
                    "Please set the Production.acemd.{f:} property to "
                    "point to the {f:} file".format(f=field, i=inputdir))

    def _amberFixes(self):
        # AMBER specific fixes
        if self.acemd.structure.endswith(".prmtop"):
            self.acemd.parmfile = self.acemd.parameters
            self.acemd.parameters = None

    def _fb_potential2restraints(self, inputdir):
        from moleculekit.molecule import Molecule

        restraints = list()

        fb_box = np.array(self.fb_box)
        # convert fb_box to width
        width = list(
            np.concatenate(
                np.diff(np.array([fb_box[::2], fb_box[1::2]]), axis=0)))

        # If fb_box is not symmetrical
        if not np.all(fb_box[::2] == -fb_box[1::2]):
            # convert fb_box and fb_reference to fbcentre and width
            mol = Molecule(os.path.join(inputdir, self.acemd.structure))
            mol.read(os.path.join(inputdir, self.acemd.coordinates))
            fb_refcentre = (mol.get(
                "coords", sel=self.fb_reference).mean(axis=0).squeeze())

            fbcentre = list(
                np.around(
                    np.mean(np.array([fb_box[::2], fb_box[1::2]]), axis=0) +
                    fb_refcentre,
                    3,
                ))
            restraints.append(
                GroupRestraint(self.fb_selection,
                               width, [(self.fb_k, 0)],
                               fbcentre=fbcentre))
        else:
            restraints.append(
                GroupRestraint(
                    self.fb_selection,
                    width,
                    [(self.fb_k, 0)],
                    fbcentresel=self.fb_reference,
                ))

        return restraints

    def _constraints2restraints(self):

        restraints = list()
        for constr in sorted(self.constraints):
            restraints.append(
                AtomRestraint(constr, 0, [(self.constraints[constr], 0)]))

        return restraints

    def write(self, inputdir, outputdir, cisbondcheck=True):
        """Writes the production protocol and files into a folder.

        Parameters
        ----------
        inputdir : str
            Path to a directory containing the files produced by a equilibration process.
        outputdir : str
            Directory where to write the production setup files.
        cisbondcheck : bool
            Set to False to disable the cis peptidic bond checks
        """
        from moleculekit.molecule import Molecule
        from htmd.units import convert
        from htmd.builder.builder import detectCisPeptideBonds

        self._findFiles(inputdir)
        self._amberFixes()

        self.acemd.temperature = self.temperature
        self.acemd.thermostattemperature = self.temperature

        numsteps = convert(self.timeunits,
                           "timesteps",
                           self.runtime,
                           timestep=self.acemd.timestep)
        self.acemd.run = str(numsteps)

        structfile = os.path.join(inputdir, self.acemd.structure)
        pdbfile = os.path.join(inputdir, self.acemd.coordinates)
        inmol = Molecule([structfile, pdbfile])

        if cisbondcheck:
            detectCisPeptideBonds(inmol, respect_bonds=True)

        if np.any(inmol.atomselect("lipids")) and not self.useconstantratio:
            logger.warning(
                "Lipids detected in input structure. We highly recommend setting useconstantratio=True "
                "for membrane simulations.")

        if self.restraints is not None:
            logger.info(
                "Using user-provided restraints and ignoring constraints and fb_potential"
            )
            self.acemd.restraints = self.restraints
        else:
            restraints = list()
            if self.fb_k > 0:
                logger.warning(
                    "Converting fb_potential to restraints. This is a convenience "
                    "functional conversion. We recommend to start using restraints."
                )
                restraints += self._fb_potential2restraints(inputdir)
            if self.useconstraints:
                logger.warning(
                    "Converting constraints to restraints. This is a convenience "
                    "functional conversion. We recommend to start using restraints"
                )
                restraints += self._constraints2restraints()
            else:
                if len(self.constraints) != 0:
                    logger.warning(
                        "You have setup constraints to {} but constraints are turned off. "
                        "If you want to use constraints, define "
                        "useconstraints=True".format(self.constraints))
            if len(restraints) != 0:
                self.acemd.restraints = restraints

        if self.useconstantratio:
            self.acemd.barostatconstratio = "on"

        if self.adaptive:
            self.acemd.binvelocities = None

        self.acemd.setup(inputdir, outputdir, overwrite=True)

    def addConstraint(self, atomselect, factor=1):
        """Convenience function for adding a new constraint to existing constraints.

        Parameters
        ----------
        atomselect : str
            Atom selection of atoms we want to constrain
        factor : float
            The scaling factor of the constraints applied to the atoms

        Example
        -------
        >>> eq.addConstraint('chain X', 0.3)
        """
        self.constraints[atomselect] = factor
Beispiel #9
0
class Equilibration(ProtocolInterface):
    """ Equilibration protocol v2

        Equilibration protocol for globular and membrane proteins
        It includes a flatbottom potential box to retrain a ligand
        for example within this box.

        Parameters
        ----------
        runtime : float, default=0
            Running time of the simulation.
        timeunits : str, default='steps'
            Units for time arguments. Can be 'steps', 'ns' etc.
        temperature : float, default=300
            Temperature of the thermostat in Kelvin
        fb_k : float, default=0
            Force constant of the flatbottom potential in kcal/mol/A^2. E.g. 5
        fb_reference : str, default='none'
            Reference selection to use as dynamic center of the flatbottom box.
        fb_selection : str, default='none'
            Selection of atoms to apply the flatbottom potential
        fb_box : list, default=[0, 0, 0, 0, 0, 0]
            Position of the flatbottom box in term of the reference center given as [xmin, xmax, ymin, ymax, zmin, zmax]
        useconstantratio : bool, default=False
            For membrane protein simulations set it to true so that the barostat does not modify the xy aspect ratio.
        constraints : dict, default={'protein and name CA': 1, 'protein and noh and not name CA': 0.1}
            A dictionary of atomselections and values of the constraint to be applied (in kcal/mol/A^2). Atomselects must be mutually exclusive.
        nvtsteps : int, default=500
            Number of initial steps to apply NVT in units of 4fs.
        constraintsteps : int, default=None
            Number of initial steps to apply constraints in units of 4fs. Defaults to half the simulation time.

        Example
        -------
        >>> from htmd.protocols.equilibration_v2 import Equilibration
        >>> md = Equilibration()
        >>> md.runtime = 4
        >>> md.timeunits = 'ns'
        >>> md.temperature = 300
        >>> md.useconstantratio = True  # only for membrane sims
        >>> # this is only needed for setting the flatbottom potential, otherwise remove it
        >>> md.fb_reference = 'protein and resid 293'
        >>> md.fb_selection = 'segname L and noh'
        >>> md.fb_box = [-25, 25, -25, 25, 43, 45]
        >>> md.fb_k = 5
        >>> md.write('./build','./equil')
    """
    def __init__(self, _version=_config['acemdversion']):
        super().__init__()
        self._version = _version
        self._arg(
            'acemd',
            ':class:`Acemd2 <htmd.apps.acemd.Acemd>` or :class:`Acemd <htmd.mdengine.acemd.acemd.Acemd>`'
            ' object', 'Acemd class object', None, val.Object([Acemd2, Acemd]))
        self._arg('runtime', 'float', 'Running time of the simulation.', 25000,
                  val.Number(float, '0POS'))
        self._arg('timeunits', 'str',
                  'Units for time arguments. Can be \'steps\', \'ns\' etc.',
                  'steps', val.String())
        self._arg('temperature', 'float',
                  'Temperature of the thermostat in Kelvin', 300,
                  val.Number(float, 'ANY'))

        self._arg(
            'fb_k', 'float',
            'Force constant of the flatbottom potential in kcal/mol/A^2. E.g. 5',
            0, val.Number(float, 'ANY'))
        self._arg(
            'fb_reference', 'str',
            'Reference selection to use as dynamic center of the flatbottom box.',
            'none', val.String())
        self._arg('fb_selection', 'str',
                  'Selection of atoms to apply the flatbottom potential',
                  'none', val.String())
        self._arg(
            'fb_box',
            'list',
            'Position of the flatbottom box in term of the reference center given as '
            '[xmin, xmax, ymin, ymax, zmin, zmax]', [0, 0, 0, 0, 0, 0],
            val.Number(float, 'ANY'),
            nargs=6)

        self._arg(
            'constraints', 'dict',
            'A dictionary of atomselections and values of the constraint to be '
            'applied (in kcal/mol/A^2). Atomselects must be mutually exclusive.',
            {
                'protein and noh and not name CA': 0.1,
                'protein and name CA': 1
            }, val.Dictionary(key_type=str))
        self._arg(
            'useconstantratio', 'bool',
            'For membrane protein simulations set it to true so that the barostat '
            'does not modify the xy aspect ratio.', False, val.Boolean())

        self._arg('nvtsteps', 'int',
                  'Number of initial steps to apply NVT in units of 4fs.', 500,
                  val.Number(int, 'ANY'))
        self._arg(
            'constraintsteps', 'int',
            'Number of initial steps to apply constraints in units of 4fs. Defaults '
            'to half the simulation time.', None, val.Number(int, 'ANY'))
        self._arg(
            'restraints',
            'list',
            'A list of restraint objects. Only works with {}(_version=3),'
            'see :class:`AtomRestraint <htmd.mdengine.acemd.acemd.AtomRestraint>` and'
            ':class:`GroupRestraint <htmd.mdengine.acemd.acemd.GroupRestraint>`'
            ')'.format(self.__class__.__name__),
            None,
            val.Object(_Restraint),
            nargs='*')

        if self._version == 2:
            self.acemd = Acemd2()
            self.acemd.coordinates = None
            self.acemd.structure = None
            self.acemd.parameters = None
            self.acemd.temperature = '$temperature'
            self.acemd.restart = 'on'
            self.acemd.restartfreq = '5000'
            self.acemd.outputname = 'output'
            self.acemd.xtcfile = 'output.xtc'
            self.acemd.xtcfreq = '25000'
            self.acemd.timestep = '4'
            self.acemd.rigidbonds = 'all'
            self.acemd.hydrogenscale = '4'
            self.acemd.switching = 'on'
            self.acemd.switchdist = '7.5'
            self.acemd.cutoff = '9'
            self.acemd.exclude = 'scaled1-4'
            self.acemd.scaling14 = '1.0'
            self.acemd.langevin = 'on'
            self.acemd.langevintemp = '$temperature'
            self.acemd.langevindamping = '1'
            self.acemd.pme = 'on'
            self.acemd.pmegridspacing = '1.0'
            self.acemd.fullelectfrequency = '2'
            self.acemd.energyfreq = '1000'
            self.acemd.constraints = 'on'
            self.acemd.consref = None
            self.acemd.constraintscaling = '1.0'
            self.acemd.berendsenpressure = 'on'
            self.acemd.berendsenpressuretarget = '1.01325'
            self.acemd.berendsenpressurerelaxationtime = '800'
            self.acemd.tclforces = 'on'
            self.acemd.minimize = '500'
            self.acemd.run = '$numsteps'
            self.acemd.TCL = ('''
set numsteps {NUMSTEPS}
set temperature {TEMPERATURE}
set nvtsteps {NVTSTEPS}
set constraintsteps {CONSTRAINTSTEPS}
set fb_refindex {{ {REFINDEX} }}
set fb_selindex {{ {SELINDEX} }}
set fb_box {{ {BOX} }}
set fb_K {KCONST}
#
''', '''
proc flatbot1d {x xm xM fb_K} {
  set f 0
  if {$x < $xm} {
    set f [expr $fb_K*[expr $xm-$x]]
  }
  if {$x > $xM} {
    set f [expr $fb_K*[expr $xM-$x]]
  }
  return $f
}
proc calcforces_init {} {
  global ref sel fb_refindex fb_selindex
  berendsenpressure  off
  set ref [addgroup  $fb_refindex]
  set sel [addgroup  $fb_selindex]
}
proc calcforces {} {
  global ref sel numsteps fb_K fb_box nvtsteps constraintsteps
  loadcoords coords
##FLATBOTTOM
  if {$fb_K>0} {
    set r0 $coords($ref)
    set r1 $coords($sel)
    set dr  [vecsub $r1 $r0]
    set fx [flatbot1d [lindex $dr 0] [lindex $fb_box 0] [lindex $fb_box 1] $fb_K]
    set fy [flatbot1d [lindex $dr 1] [lindex $fb_box 2] [lindex $fb_box 3] $fb_K]
    set fz [flatbot1d [lindex $dr 2] [lindex $fb_box 4] [lindex $fb_box 5] $fb_K]
    #print "dr: $dr  fx: $fx fy: $fy fz: $fz"
    addforce $sel [list $fx $fy $fz]
  }
##EQUIL
  set step [ getstep ]
  if { $step > $nvtsteps } {
    berendsenpressure  on
  } else {
    berendsenpressure  off
  }
  if { $step > $constraintsteps } {
    constraintscaling 0
  } else {
    constraintscaling [expr 1 - 0.95*$step/$constraintsteps]
  }
}
proc calcforces_endstep { } { }
''')
        elif self._version == 3:
            self.acemd = Acemd()
            self.acemd.coordinates = None
            self.acemd.structure = None
            self.acemd.parameters = None
            self.acemd.restart = 'on'
            self.acemd.trajectoryfile = 'output.xtc'
            self.acemd.trajectoryperiod = 25000
            self.acemd.timestep = 4
            self.acemd.switching = 'on'
            self.acemd.switchdistance = 7.5
            self.acemd.cutoff = 9
            self.acemd.thermostat = 'on'
            self.acemd.thermostatdamping = 1
            self.acemd.pme = 'on'
            self.acemd.barostat = 'on'
            self.acemd.barostatpressure = 1.01325
            self.acemd.minimize = 500
        else:
            raise ValueError(
                '_version can not be {}. Choose either 2 or 3.'.format(
                    self._version))

    def _findFiles(self, inputdir):
        # Tries to find default files if the given don't exist
        defaults = {
            'coordinates': ('structure.pdb', ),
            'structure': ('structure.psf', 'structure.prmtop'),
            'parameters': ('parameters', 'structure.prmtop')
        }

        for field in defaults:
            userval = self.acemd.__dict__[field]
            if userval is not None and not os.path.exists(
                    os.path.join(inputdir, userval)):
                self.acemd.__dict__[field] = None

            if self.acemd.__dict__[field] is None:
                for val in defaults[field]:
                    if os.path.exists(os.path.join(inputdir, val)):
                        self.acemd.__dict__[field] = val
                        break

            if userval is not None and self.acemd.__dict__[
                    field] is not None and self.acemd.__dict__[
                        field] != userval:
                logger.warning(
                    'Could not locate structure file {}. Using {} instead.'.
                    format(os.path.join(inputdir, userval),
                           os.path.join(inputdir, self.acemd.__dict__[field])))
            elif self.acemd.__dict__[field] is None:
                raise RuntimeError(
                    'Could not locate any {f:} file in {i:}. '
                    'Please set the {name:}.acemd.{f:} property to '
                    'point to the {f:} file'.format(
                        f=field, i=inputdir, name=self.__class__.__name__))

        if self._version == 2:
            if self.acemd.consref is None:
                self.acemd.consref = self.acemd.coordinates

    def _amberFixes(self):
        # AMBER specific fixes
        if self.acemd.parameters.endswith('structure.prmtop'):
            self.acemd.parmfile = self.acemd.parameters
            self.acemd.parameters = None
            if self._version == 2:
                self.acemd.scaling14 = '0.8333333'
                self.acemd.amber = 'on'

    def _constraints2restraints(self, constrsteps):

        restraints = list()
        for constr in sorted(self.constraints):
            restraints.append(
                AtomRestraint(constr, 0, [(self.constraints[constr], 0),
                                          (0, constrsteps)]))

        return restraints

    def _fb_potential2restraints(self, inputdir):
        from moleculekit.molecule import Molecule
        restraints = list()

        fb_box = np.array(self.fb_box)
        # convert fb_box to width
        width = list(
            np.concatenate(
                np.diff(np.array([fb_box[::2], fb_box[1::2]]), axis=0)))

        # If fb_box is not symmetrical
        if not np.all(fb_box[::2] == -fb_box[1::2]):
            # convert fb_box and fb_reference to fbcentre and width
            mol = Molecule(os.path.join(inputdir, self.acemd.structure))
            mol.read(os.path.join(inputdir, self.acemd.coordinates))
            fb_refcentre = mol.get(
                'coords', sel=self.fb_reference).mean(axis=0).squeeze()

            fbcentre = list(
                np.around(
                    np.mean(np.array([fb_box[::2], fb_box[1::2]]), axis=0) +
                    fb_refcentre, 3))
            restraints.append(
                GroupRestraint(self.fb_selection,
                               width, [(self.fb_k, 0)],
                               fbcentre=fbcentre))
        else:
            restraints.append(
                GroupRestraint(self.fb_selection,
                               width, [(self.fb_k, 0)],
                               fbcentresel=self.fb_reference))

        return restraints

    def write(self, inputdir, outputdir):
        """ Write the equilibration protocol

        Writes the equilibration protocol and files into a folder for execution
        using files inside the inputdir directory

        Parameters
        ----------
        inputdir : str
            Path to a directory containing the files produced by a build process.
        outputdir : str
            Directory where to write the equilibration setup files.

        Examples
        --------
        >>> md = Equilibration()
        >>> md.write('./build','./equil')
        """

        from moleculekit.molecule import Molecule

        # Do version consistency check
        if (self._version == 2 and not isinstance(self.acemd, Acemd2)) and \
                (self._version == 3 and not isinstance(self.acemd, Acemd)):
            raise RuntimeError(
                'Acemd object version ({}) inconsistent with protocol version at instantiation '
                '({})'.format(type(self.acemd), self._version))

        self._findFiles(inputdir)
        self._amberFixes()

        from htmd.units import convert
        numsteps = convert(self.timeunits,
                           'timesteps',
                           self.runtime,
                           timestep=self.acemd.timestep)
        if self._version == 3:
            self.acemd.temperature = self.temperature
            self.acemd.thermostattemperature = self.temperature
            self.acemd.run = str(numsteps)

        pdbfile = os.path.join(inputdir, self.acemd.coordinates)
        inmol = Molecule(pdbfile)

        from htmd.builder.builder import detectCisPeptideBonds
        detectCisPeptideBonds(inmol)

        if np.any(inmol.atomselect('lipids')) and not self.useconstantratio:
            logger.warning(
                'Lipids detected in input structure. We highly recommend setting useconstantratio=True '
                'for membrane simulations.')

        if self.constraintsteps is None:
            constrsteps = int(numsteps / 2)
        else:
            constrsteps = int(self.constraintsteps)

        if self._version == 2:
            if self.restraints:
                raise RuntimeWarning(
                    'restraints are only available on {}(_version=3)'.format(
                        self.__class__.__name__))
            if isinstance(self.acemd.TCL, tuple):
                tcl = list(self.acemd.TCL)
                tcl[0] = tcl[0].format(
                    NUMSTEPS=numsteps,
                    KCONST=self.fb_k,
                    REFINDEX=' '.join(
                        map(str, inmol.get('index', self.fb_reference))),
                    SELINDEX=' '.join(
                        map(str, inmol.get('index', self.fb_selection))),
                    BOX=' '.join(map(str, self.fb_box)),
                    NVTSTEPS=self.nvtsteps,
                    CONSTRAINTSTEPS=constrsteps,
                    TEMPERATURE=self.temperature)
                self.acemd.TCL = tcl[0] + tcl[1]
            else:
                logger.warning('{} default TCL was already formatted.'.format(
                    self.__class__.__name__))
        elif self._version == 3:
            if self.restraints is not None:
                logger.info(
                    'Using user-provided restraints and ignoring constraints and fb_potential'
                )
                self.acemd.restraints = self.restraints
            else:
                logger.warning(
                    'Converting constraints and fb_potential to restraints. This is a convenience '
                    'functional conversion. We recommend start using restraints with '
                    '{}(_version=3)'.format(self.__class__.__name__))
                restraints = list()
                # convert constraints to restraints and add them
                if self.constraints is not None:
                    restraints += self._constraints2restraints(constrsteps)
                # convert fb_potential to restraints and add them
                if self.fb_k > 0:
                    restraints += self._fb_potential2restraints(inputdir)
                self.acemd.restraints = restraints

        if ((self._version == 2) and self.acemd.celldimension is None and self.acemd.extendedsystem is None) or \
            ((self._version == 3) and self.acemd.boxsize is None and self.acemd.extendedsystem is None):
            coords = inmol.get('coords', sel='water')
            if coords.size == 0:  # It's a vacuum simulation
                coords = inmol.get('coords', sel='all')
                dim = np.max(coords, axis=0) - np.min(coords, axis=0)
                dim += 12.
            else:
                dim = np.max(coords, axis=0) - np.min(coords, axis=0)
            if self._version == 2:
                self.acemd.celldimension = '{} {} {}'.format(
                    dim[0], dim[1], dim[2])
            else:
                self.acemd.boxsize = '{} {} {}'.format(dim[0], dim[1], dim[2])

        if self.useconstantratio:
            self.acemd.useconstantratio = 'on'

        self.acemd.setup(inputdir, outputdir, overwrite=True)

        if self._version == 2:
            # Adding constraints by writing them to the consref file
            inconsreffile = os.path.join(inputdir, self.acemd.consref)
            consrefmol = Molecule(inconsreffile)
            consrefmol.set('occupancy', 0)
            consrefmol.set('beta', 0)
            if len(self.constraints) == 0:
                raise RuntimeError(
                    'You have not defined any constraints for the {} ('
                    'constraints={{}}).'.format(self.__class__.__name__))
            else:
                for sel in self.constraints:
                    consrefmol.set('beta', self.constraints[sel], sel)
            outconsreffile = os.path.join(outputdir, self.acemd.consref)
            consrefmol.write(outconsreffile)

    def addConstraint(self, atomselect, factor=1):
        """ Convenience function for adding a new constraint to existing constraints.

        Parameters
        ----------
        atomselect : str
            Atom selection of atoms we want to constrain
        factor : float
            The scaling factor of the constraints applied to the atoms

        Example
        -------
        >>> eq.addConstraint('chain X', 0.3)
        """
        self.constraints[atomselect] = factor