예제 #1
0
    def create_hamiltonian(self, realspace, mode, xc):
        dens = self.density
        kwargs = dict(gd=dens.gd,
                      finegd=dens.finegd,
                      nspins=dens.nspins,
                      collinear=dens.collinear,
                      setups=dens.setups,
                      timer=self.timer,
                      xc=xc,
                      world=self.world,
                      redistributor=dens.redistributor,
                      vext=self.parameters.external,
                      psolver=self.parameters.poissonsolver)
        if realspace:
            self.hamiltonian = RealSpaceHamiltonian(stencil=mode.interpolation,
                                                    **kwargs)
            xc.set_grid_descriptor(self.hamiltonian.finegd)
        else:
            # This code will work if dens.redistributor uses
            # ordinary density.gd as aux_gd
            gd = dens.finegd

            xc_redist = None
            if self.parallel['augment_grids']:
                from gpaw.grid_descriptor import BadGridError
                try:
                    aux_gd = gd.new_descriptor(comm=self.world)
                except BadGridError as err:
                    import warnings
                    warnings.warn('Ignoring augment_grids: {}'.format(err))
                else:
                    bcast_comm = dens.redistributor.broadcast_comm
                    xc_redist = GridRedistributor(self.world, bcast_comm, gd,
                                                  aux_gd)

            self.hamiltonian = pw.ReciprocalSpaceHamiltonian(
                pd2=dens.pd2,
                pd3=dens.pd3,
                realpbc_c=self.atoms.pbc,
                xc_redistributor=xc_redist,
                **kwargs)
            xc.set_grid_descriptor(self.hamiltonian.xc_gd)

        self.hamiltonian.soc = self.parameters.experimental.get('soc')
        self.log(self.hamiltonian, '\n')
예제 #2
0
    def create_hamiltonian(self, realspace, mode, xc):
        dens = self.density
        kwargs = dict(gd=dens.gd,
                      finegd=dens.finegd,
                      nspins=dens.nspins,
                      setups=dens.setups,
                      timer=self.timer,
                      xc=xc,
                      world=self.world,
                      redistributor=dens.redistributor,
                      vext=self.parameters.external,
                      psolver=self.parameters.poissonsolver)
        if realspace:
            self.hamiltonian = RealSpaceHamiltonian(stencil=mode.interpolation,
                                                    **kwargs)
            xc.set_grid_descriptor(self.hamiltonian.finegd)  # XXX
        else:
            self.hamiltonian = pw.ReciprocalSpaceHamiltonian(
                pd2=dens.pd2, pd3=dens.pd3, realpbc_c=self.atoms.pbc, **kwargs)
            xc.set_grid_descriptor(dens.xc_redistributor.aux_gd)  # XXX

        self.log(self.hamiltonian, '\n')
예제 #3
0
    def initialize(self, atoms=None):
        """Inexpensive initialization."""

        if atoms is None:
            atoms = self.atoms
        else:
            # Save the state of the atoms:
            self.atoms = atoms.copy()

        par = self.input_parameters

        world = par.communicator
        if world is None:
            world = mpi.world
        elif hasattr(world, 'new_communicator'):
            # Check for whether object has correct type already
            #
            # Using isinstance() is complicated because of all the
            # combinations, serial/parallel/debug...
            pass
        else:
            # world should be a list of ranks:
            world = mpi.world.new_communicator(np.asarray(world))
        self.wfs.world = world

        if 'txt' in self._changed_keywords:
            self.set_txt(par.txt)
        self.verbose = par.verbose

        natoms = len(atoms)

        cell_cv = atoms.get_cell() / Bohr
        pbc_c = atoms.get_pbc()
        Z_a = atoms.get_atomic_numbers()
        magmom_av = atoms.get_initial_magnetic_moments()

        self.check_atoms()

        # Generate new xc functional only when it is reset by set
        # XXX sounds like this should use the _changed_keywords dictionary.
        if self.hamiltonian is None or self.hamiltonian.xc is None:
            if isinstance(par.xc, str):
                xc = XC(par.xc)
            else:
                xc = par.xc
        else:
            xc = self.hamiltonian.xc

        mode = par.mode

        if mode == 'fd':
            mode = FD()
        elif mode == 'pw':
            mode = pw.PW()
        elif mode == 'lcao':
            mode = LCAO()
        else:
            assert hasattr(mode, 'name'), str(mode)

        if xc.orbital_dependent and mode.name == 'lcao':
            raise NotImplementedError('LCAO mode does not support '
                                      'orbital-dependent XC functionals.')

        if par.realspace is None:
            realspace = (mode.name != 'pw')
        else:
            realspace = par.realspace
            if mode.name == 'pw':
                assert not realspace

        if par.filter is None and mode.name != 'pw':
            gamma = 1.6
            if par.gpts is not None:
                h = ((np.linalg.inv(cell_cv)**2).sum(0)**-0.5 / par.gpts).max()
            else:
                h = (par.h or 0.2) / Bohr

            def filter(rgd, rcut, f_r, l=0):
                gcut = np.pi / h - 2 / rcut / gamma
                f_r[:] = rgd.filter(f_r, rcut * gamma, gcut, l)
        else:
            filter = par.filter

        setups = Setups(Z_a, par.setups, par.basis, par.lmax, xc, filter,
                        world)

        if magmom_av.ndim == 1:
            collinear = True
            magmom_av, magmom_a = np.zeros((natoms, 3)), magmom_av
            magmom_av[:, 2] = magmom_a
        else:
            collinear = False

        magnetic = magmom_av.any()

        spinpol = par.spinpol
        if par.hund:
            if natoms != 1:
                raise ValueError('hund=True arg only valid for single atoms!')
            spinpol = True
            magmom_av[0] = (0, 0, setups[0].get_hunds_rule_moment(par.charge))

        if spinpol is None:
            spinpol = magnetic
        elif magnetic and not spinpol:
            raise ValueError('Non-zero initial magnetic moment for a ' +
                             'spin-paired calculation!')

        if collinear:
            nspins = 1 + int(spinpol)
            ncomp = 1
        else:
            nspins = 1
            ncomp = 2

        if par.usesymm != 'default':
            warnings.warn('Use "symmetry" keyword instead of ' +
                          '"usesymm" keyword')
            par.symmetry = usesymm2symmetry(par.usesymm)

        symm = par.symmetry
        if symm == 'off':
            symm = {'point_group': False, 'time_reversal': False}

        bzkpts_kc = kpts2ndarray(par.kpts, self.atoms)
        kd = KPointDescriptor(bzkpts_kc, nspins, collinear)
        m_av = magmom_av.round(decimals=3)  # round off
        id_a = zip(setups.id_a, *m_av.T)
        symmetry = Symmetry(id_a, cell_cv, atoms.pbc, **symm)
        kd.set_symmetry(atoms, symmetry, comm=world)
        setups.set_symmetry(symmetry)

        if par.gpts is not None:
            N_c = np.array(par.gpts)
        else:
            h = par.h
            if h is not None:
                h /= Bohr
            N_c = get_number_of_grid_points(cell_cv, h, mode, realspace,
                                            kd.symmetry)

        symmetry.check_grid(N_c)

        width = par.width
        if width is None:
            if pbc_c.any():
                width = 0.1  # eV
            else:
                width = 0.0
        else:
            assert par.occupations is None

        if hasattr(self, 'time') or par.dtype == complex:
            dtype = complex
        else:
            if kd.gamma:
                dtype = float
            else:
                dtype = complex

        nao = setups.nao
        nvalence = setups.nvalence - par.charge
        M_v = magmom_av.sum(0)
        M = np.dot(M_v, M_v)**0.5

        nbands = par.nbands

        orbital_free = any(setup.orbital_free for setup in setups)
        if orbital_free:
            nbands = 1

        if isinstance(nbands, basestring):
            if nbands[-1] == '%':
                basebands = int(nvalence + M + 0.5) // 2
                nbands = int((float(nbands[:-1]) / 100) * basebands)
            else:
                raise ValueError('Integer Expected: Only use a string '
                                 'if giving a percentage of occupied bands')

        if nbands is None:
            nbands = 0
            for setup in setups:
                nbands_from_atom = setup.get_default_nbands()

                # Any obscure setup errors?
                if nbands_from_atom < -(-setup.Nv // 2):
                    raise ValueError('Bad setup: This setup requests %d'
                                     ' bands but has %d electrons.' %
                                     (nbands_from_atom, setup.Nv))
                nbands += nbands_from_atom
            nbands = min(nao, nbands)
        elif nbands > nao and mode.name == 'lcao':
            raise ValueError('Too many bands for LCAO calculation: '
                             '%d bands and only %d atomic orbitals!' %
                             (nbands, nao))

        if nvalence < 0:
            raise ValueError(
                'Charge %f is not possible - not enough valence electrons' %
                par.charge)

        if nbands <= 0:
            nbands = int(nvalence + M + 0.5) // 2 + (-nbands)

        if nvalence > 2 * nbands and not orbital_free:
            raise ValueError('Too few bands!  Electrons: %f, bands: %d' %
                             (nvalence, nbands))

        nbands *= ncomp

        if par.width is not None:
            self.text('**NOTE**: please start using '
                      'occupations=FermiDirac(width).')
        if par.fixmom:
            self.text('**NOTE**: please start using '
                      'occupations=FermiDirac(width, fixmagmom=True).')

        if self.occupations is None:
            if par.occupations is None:
                # Create object for occupation numbers:
                if orbital_free:
                    width = 0.0  # even for PBC
                    self.occupations = occupations.TFOccupations(
                        width, par.fixmom)
                else:
                    self.occupations = occupations.FermiDirac(
                        width, par.fixmom)
            else:
                self.occupations = par.occupations

            # If occupation numbers are changed, and we have wave functions,
            # recalculate the occupation numbers
            if self.wfs is not None and not isinstance(self.wfs,
                                                       EmptyWaveFunctions):
                self.occupations.calculate(self.wfs)

        self.occupations.magmom = M_v[2]

        cc = par.convergence

        if mode.name == 'lcao':
            niter_fixdensity = 0
        else:
            niter_fixdensity = None

        if self.scf is None:
            force_crit = cc['forces']
            if force_crit is not None:
                force_crit /= Hartree / Bohr
            self.scf = SCFLoop(cc['eigenstates'] / Hartree**2 * nvalence,
                               cc['energy'] / Hartree * max(nvalence, 1),
                               cc['density'] * nvalence, par.maxiter,
                               par.fixdensity, niter_fixdensity, force_crit)

        parsize_kpt = par.parallel['kpt']
        parsize_domain = par.parallel['domain']
        parsize_bands = par.parallel['band']

        if not realspace:
            pbc_c = np.ones(3, bool)

        if not self.wfs:
            if parsize_domain == 'domain only':  # XXX this was silly!
                parsize_domain = world.size

            parallelization = mpi.Parallelization(world, nspins * kd.nibzkpts)
            ndomains = None
            if parsize_domain is not None:
                ndomains = np.prod(parsize_domain)
            if mode.name == 'pw':
                if ndomains > 1:
                    raise ValueError('Planewave mode does not support '
                                     'domain decomposition.')
                ndomains = 1
            parallelization.set(kpt=parsize_kpt,
                                domain=ndomains,
                                band=parsize_bands)
            comms = parallelization.build_communicators()
            domain_comm = comms['d']
            kpt_comm = comms['k']
            band_comm = comms['b']
            kptband_comm = comms['D']
            domainband_comm = comms['K']

            self.comms = comms
            kd.set_communicator(kpt_comm)

            parstride_bands = par.parallel['stridebands']

            # Unfortunately we need to remember that we adjusted the
            # number of bands so we can print a warning if it differs
            # from the number specified by the user.  (The number can
            # be inferred from the input parameters, but it's tricky
            # because we allow negative numbers)
            self.nbands_parallelization_adjustment = -nbands % band_comm.size
            nbands += self.nbands_parallelization_adjustment

            # I would like to give the following error message, but apparently
            # there are cases, e.g. gpaw/test/gw_ppa.py, which involve
            # nbands > nao and are supposed to work that way.
            #if nbands > nao:
            #    raise ValueError('Number of bands %d adjusted for band '
            #                     'parallelization %d exceeds number of atomic '
            #                     'orbitals %d.  This problem can be fixed '
            #                     'by reducing the number of bands a bit.'
            #                     % (nbands, band_comm.size, nao))
            bd = BandDescriptor(nbands, band_comm, parstride_bands)

            if (self.density is not None
                    and self.density.gd.comm.size != domain_comm.size):
                # Domain decomposition has changed, so we need to
                # reinitialize density and hamiltonian:
                if par.fixdensity:
                    raise RuntimeError(
                        'Density reinitialization conflict ' +
                        'with "fixdensity" - specify domain decomposition.')
                self.density = None
                self.hamiltonian = None

            # Construct grid descriptor for coarse grids for wave functions:
            gd = self.grid_descriptor_class(N_c, cell_cv, pbc_c, domain_comm,
                                            parsize_domain)

            # do k-point analysis here? XXX
            args = (gd, nvalence, setups, bd, dtype, world, kd, kptband_comm,
                    self.timer)

            if par.parallel['sl_auto']:
                # Choose scalapack parallelization automatically

                for key, val in par.parallel.items():
                    if (key.startswith('sl_') and key != 'sl_auto'
                            and val is not None):
                        raise ValueError("Cannot use 'sl_auto' together "
                                         "with '%s'" % key)
                max_scalapack_cpus = bd.comm.size * gd.comm.size
                nprow = max_scalapack_cpus
                npcol = 1

                # Get a sort of reasonable number of columns/rows
                while npcol < nprow and nprow % 2 == 0:
                    npcol *= 2
                    nprow //= 2
                assert npcol * nprow == max_scalapack_cpus

                # ScaLAPACK creates trouble if there aren't at least a few
                # whole blocks; choose block size so there will always be
                # several blocks.  This will crash for small test systems,
                # but so will ScaLAPACK in any case
                blocksize = min(-(-nbands // 4), 64)
                sl_default = (nprow, npcol, blocksize)
            else:
                sl_default = par.parallel['sl_default']

            if mode.name == 'lcao':
                # Layouts used for general diagonalizer
                sl_lcao = par.parallel['sl_lcao']
                if sl_lcao is None:
                    sl_lcao = sl_default
                lcaoksl = get_KohnSham_layouts(sl_lcao,
                                               'lcao',
                                               gd,
                                               bd,
                                               domainband_comm,
                                               dtype,
                                               nao=nao,
                                               timer=self.timer)

                self.wfs = mode(collinear, lcaoksl, *args)

            elif mode.name == 'fd' or mode.name == 'pw':
                # buffer_size keyword only relevant for fdpw
                buffer_size = par.parallel['buffer_size']
                # Layouts used for diagonalizer
                sl_diagonalize = par.parallel['sl_diagonalize']
                if sl_diagonalize is None:
                    sl_diagonalize = sl_default
                diagksl = get_KohnSham_layouts(
                    sl_diagonalize,
                    'fd',  # XXX
                    # choice of key 'fd' not so nice
                    gd,
                    bd,
                    domainband_comm,
                    dtype,
                    buffer_size=buffer_size,
                    timer=self.timer)

                # Layouts used for orthonormalizer
                sl_inverse_cholesky = par.parallel['sl_inverse_cholesky']
                if sl_inverse_cholesky is None:
                    sl_inverse_cholesky = sl_default
                if sl_inverse_cholesky != sl_diagonalize:
                    message = 'sl_inverse_cholesky != sl_diagonalize ' \
                        'is not implemented.'
                    raise NotImplementedError(message)
                orthoksl = get_KohnSham_layouts(sl_inverse_cholesky,
                                                'fd',
                                                gd,
                                                bd,
                                                domainband_comm,
                                                dtype,
                                                buffer_size=buffer_size,
                                                timer=self.timer)

                # Use (at most) all available LCAO for initialization
                lcaonbands = min(nbands, nao)

                try:
                    lcaobd = BandDescriptor(lcaonbands, band_comm,
                                            parstride_bands)
                except RuntimeError:
                    initksl = None
                else:
                    # Layouts used for general diagonalizer
                    # (LCAO initialization)
                    sl_lcao = par.parallel['sl_lcao']
                    if sl_lcao is None:
                        sl_lcao = sl_default
                    initksl = get_KohnSham_layouts(sl_lcao,
                                                   'lcao',
                                                   gd,
                                                   lcaobd,
                                                   domainband_comm,
                                                   dtype,
                                                   nao=nao,
                                                   timer=self.timer)

                if hasattr(self, 'time'):
                    assert mode.name == 'fd'
                    from gpaw.tddft import TimeDependentWaveFunctions
                    self.wfs = TimeDependentWaveFunctions(
                        par.stencils[0], diagksl, orthoksl, initksl, gd,
                        nvalence, setups, bd, world, kd, kptband_comm,
                        self.timer)
                elif mode.name == 'fd':
                    self.wfs = mode(par.stencils[0], diagksl, orthoksl,
                                    initksl, *args)
                else:
                    assert mode.name == 'pw'
                    self.wfs = mode(diagksl, orthoksl, initksl, *args)
            else:
                self.wfs = mode(self, *args)
        else:
            self.wfs.set_setups(setups)

        if not self.wfs.eigensolver:
            # Number of bands to converge:
            nbands_converge = cc['bands']
            if nbands_converge == 'all':
                nbands_converge = nbands
            elif nbands_converge != 'occupied':
                assert isinstance(nbands_converge, int)
                if nbands_converge < 0:
                    nbands_converge += nbands
            eigensolver = get_eigensolver(par.eigensolver, mode,
                                          par.convergence)
            eigensolver.nbands_converge = nbands_converge
            # XXX Eigensolver class doesn't define an nbands_converge property

            if isinstance(xc, SIC):
                eigensolver.blocksize = 1
            self.wfs.set_eigensolver(eigensolver)

        if self.density is None:
            gd = self.wfs.gd
            if par.stencils[1] != 9:
                # Construct grid descriptor for fine grids for densities
                # and potentials:
                finegd = gd.refine()
            else:
                # Special case (use only coarse grid):
                finegd = gd

            if realspace:
                self.density = RealSpaceDensity(
                    gd, finegd, nspins, par.charge + setups.core_charge,
                    collinear, par.stencils[1])
            else:
                self.density = pw.ReciprocalSpaceDensity(
                    gd, finegd, nspins, par.charge + setups.core_charge,
                    collinear)

        self.density.initialize(setups, self.timer, magmom_av, par.hund)
        self.density.set_mixer(par.mixer)

        if self.hamiltonian is None:
            gd, finegd = self.density.gd, self.density.finegd
            if realspace:
                self.hamiltonian = RealSpaceHamiltonian(
                    gd, finegd, nspins, setups, self.timer, xc, world,
                    self.wfs.kptband_comm, par.external, collinear,
                    par.poissonsolver, par.stencils[1])
            else:
                self.hamiltonian = pw.ReciprocalSpaceHamiltonian(
                    gd, finegd, self.density.pd2, self.density.pd3, nspins,
                    setups, self.timer, xc, world, self.wfs.kptband_comm,
                    par.external, collinear)

        xc.initialize(self.density, self.hamiltonian, self.wfs,
                      self.occupations)

        self.text()
        self.print_memory_estimate(self.txt, maxdepth=memory_estimate_depth)
        self.txt.flush()

        self.timer.print_info(self)

        if dry_run:
            self.dry_run()

        if realspace and \
                self.hamiltonian.poisson.get_description() == 'FDTD+TDDFT':
            self.hamiltonian.poisson.set_density(self.density)
            self.hamiltonian.poisson.print_messages(self.text)
            self.txt.flush()

        self.initialized = True
        self._changed_keywords.clear()