def get_scf_kgrid(atoms, parameters):
kpts, scf_kgrid = parameters.get('kpts'), parameters.get('scf_kgrid')
if isinstance(kpts,
(tuple, list, np.ndarray)) and len(kpts) == 3 and isinstance(
kpts[0], int):
return kpts
elif isinstance(kpts, float) or isinstance(kpts, int):
return tuple(kpts2sizeandoffsets(atoms=atoms, density=kpts)[0])
else:
return scf_kgrid
def get_scf_kgrid(kpts=None, scf_kgrid=None, atoms=None):
if isinstance(kpts, tuple) or isinstance(kpts, list):
if len(kpts) == 3 and isinstance(kpts[0], int):
return kpts
elif scf_kgrid is not None:
return scf_kgrid
else:
return (4, 4, 4)
elif isinstance(kpts, float) or isinstance(kpts, int):
return tuple(kpts2sizeandoffsets(atoms=atoms, density=kpts)[0])
else:
return (4, 4, 4)
def build_kpts_str(atoms, kspacing, kpts, koffset):
'''
'''
# KPOINTS - add a MP grid as required
if kspacing is not None:
kgrid = kspacing_to_grid(atoms, kspacing)
elif kpts is not None:
if isinstance(kpts, dict) and 'path' not in kpts:
kgrid, shift = kpts2sizeandoffsets(atoms=atoms, **kpts)
koffset = []
for i, x in enumerate(shift):
assert x == 0 or abs(x * kgrid[i] - 0.5) < 1e-14
koffset.append(0 if x == 0 else 1)
else:
kgrid = kpts
else:
kgrid = "gamma"
# True and False work here and will get converted by ':d' format
if isinstance(koffset, int):
koffset = (koffset, ) * 3
# BandPath object or bandpath-as-dictionary:
if isinstance(kgrid, dict) or hasattr(kgrid, 'kpts'):
kpts_str = ['K_POINTS crystal_b\n']
assert hasattr(kgrid, 'path') or 'path' in kgrid
kgrid = kpts2ndarray(kgrid, atoms=atoms)
kpts_str.append('%s\n' % len(kgrid))
for k in kgrid:
kpts_str.append(
'{k[0]:.14f} {k[1]:.14f} {k[2]:.14f} 0\n'.format(k=k))
kpts_str.append('\n')
elif isinstance(kgrid, str) and (kgrid == "gamma"):
kpts_str = ['K_POINTS gamma\n']
kpts_str.append('\n')
else:
kpts_str = ['K_POINTS automatic\n']
kpts_str.append('{0[0]} {0[1]} {0[2]} {1[0]:d} {1[1]:d} {1[2]:d}\n'
''.format(kgrid, koffset))
kpts_str.append('\n')
return kpts_str
def __init__(self, restart=None,
ignore_bad_restart_file=FileIOCalculator._deprecated,
label='dftb', atoms=None, kpts=None,
slako_dir=None,
**kwargs):
"""
All keywords for the dftb_in.hsd input file (see the DFTB+ manual)
can be set by ASE. Consider the following input file block:
>>> Hamiltonian = DFTB {
>>> SCC = Yes
>>> SCCTolerance = 1e-8
>>> MaxAngularMomentum = {
>>> H = s
>>> O = p
>>> }
>>> }
This can be generated by the DFTB+ calculator by using the
following settings:
>>> calc = Dftb(Hamiltonian_='DFTB', # line is included by default
>>> Hamiltonian_SCC='Yes',
>>> Hamiltonian_SCCTolerance=1e-8,
>>> Hamiltonian_MaxAngularMomentum_='',
>>> Hamiltonian_MaxAngularMomentum_H='s',
>>> Hamiltonian_MaxAngularMomentum_O='p')
In addition to keywords specific to DFTB+, also the following keywords
arguments can be used:
restart: str
Prefix for restart file. May contain a directory.
Default is None: don't restart.
ignore_bad_restart_file: bool
Ignore broken or missing restart file. By default, it is an
error if the restart file is missing or broken.
label: str (default 'dftb')
Prefix used for the main output file (<label>.out).
atoms: Atoms object (default None)
Optional Atoms object to which the calculator will be
attached. When restarting, atoms will get its positions and
unit-cell updated from file.
kpts: (default None)
Brillouin zone sampling:
* ``(1,1,1)`` or ``None``: Gamma-point only
* ``(n1,n2,n3)``: Monkhorst-Pack grid
* ``dict``: Interpreted as a path in the Brillouin zone if
it contains the 'path_' keyword. Otherwise it is converted
into a Monkhorst-Pack grid using
``ase.calculators.calculator.kpts2sizeandoffsets``
* ``[(k11,k12,k13),(k21,k22,k23),...]``: Explicit (Nkpts x 3)
array of k-points in units of the reciprocal lattice vectors
(each with equal weight)
Additional attribute to be set by the embed() method:
pcpot: PointCharge object
An external point charge potential (for QM/MM calculations)
"""
if slako_dir is None:
slako_dir = os.environ.get('DFTB_PREFIX', './')
if not slako_dir.endswith('/'):
slako_dir += '/'
self.slako_dir = slako_dir
self.default_parameters = dict(
Hamiltonian_='DFTB',
Hamiltonian_SlaterKosterFiles_='Type2FileNames',
Hamiltonian_SlaterKosterFiles_Prefix=self.slako_dir,
Hamiltonian_SlaterKosterFiles_Separator='"-"',
Hamiltonian_SlaterKosterFiles_Suffix='".skf"',
Hamiltonian_MaxAngularMomentum_='',
Options_='',
Options_WriteResultsTag='Yes')
self.pcpot = None
self.lines = None
self.atoms = None
self.atoms_input = None
self.do_forces = False
self.outfilename = 'dftb.out'
FileIOCalculator.__init__(self, restart, ignore_bad_restart_file,
label, atoms,
**kwargs)
# Determine number of spin channels
try:
entry = kwargs['Hamiltonian_SpinPolarisation']
spinpol = 'colinear' in entry.lower()
except KeyError:
spinpol = False
self.nspin = 2 if spinpol else 1
# kpoint stuff by ase
self.kpts = kpts
self.kpts_coord = None
if self.kpts is not None:
initkey = 'Hamiltonian_KPointsAndWeights'
mp_mesh = None
offsets = None
if isinstance(self.kpts, dict):
if 'path' in self.kpts:
# kpts is path in Brillouin zone
self.parameters[initkey + '_'] = 'Klines '
self.kpts_coord = kpts2ndarray(self.kpts, atoms=atoms)
else:
# kpts is (implicit) definition of
# Monkhorst-Pack grid
self.parameters[initkey + '_'] = 'SupercellFolding '
mp_mesh, offsets = kpts2sizeandoffsets(atoms=atoms,
**self.kpts)
elif np.array(self.kpts).ndim == 1:
# kpts is Monkhorst-Pack grid
self.parameters[initkey + '_'] = 'SupercellFolding '
mp_mesh = self.kpts
offsets = [0.] * 3
elif np.array(self.kpts).ndim == 2:
# kpts is (N x 3) list/array of k-point coordinates
# each will be given equal weight
self.parameters[initkey + '_'] = ''
self.kpts_coord = np.array(self.kpts)
else:
raise ValueError('Illegal kpts definition:' + str(self.kpts))
if mp_mesh is not None:
eps = 1e-10
for i in range(3):
key = initkey + '_empty%03d' % i
val = [mp_mesh[i] if j == i else 0 for j in range(3)]
self.parameters[key] = ' '.join(map(str, val))
offsets[i] *= mp_mesh[i]
assert abs(offsets[i]) < eps or abs(offsets[i] - 0.5) < eps
# DFTB+ uses a different offset convention, where
# the k-point mesh is already Gamma-centered prior
# to the addition of any offsets
if mp_mesh[i] % 2 == 0:
offsets[i] += 0.5
key = initkey + '_empty%03d' % 3
self.parameters[key] = ' '.join(map(str, offsets))
elif self.kpts_coord is not None:
for i, c in enumerate(self.kpts_coord):
key = initkey + '_empty%09d' % i
c_str = ' '.join(map(str, c))
if 'Klines' in self.parameters[initkey + '_']:
c_str = '1 ' + c_str
else:
c_str += ' 1.0'
self.parameters[key] = c_str
def __init__(self, restart=None, ignore_bad_restart_file=False,
label='dftb', atoms=None, kpts=None,
run_manyDftb_steps=False,
**kwargs):
"""Construct a DFTB+ calculator.
run_manyDftb_steps: Logical
True: many steps are run by DFTB+,
False:a single force&energy calculation at given positions
kpts: (int, int, int), dict, or 2D-array
If kpts is a tuple (or list) of 3 integers, it is interpreted
as the dimensions of a Monkhorst-Pack grid.
If kpts is a dict, it will either be interpreted as a path
in the Brillouin zone (*) if it contains the 'path' keyword,
otherwise it is converted to a Monkhorst-Pack grid (**).
(*) see ase.dft.kpoints.bandpath
(**) see ase.calculators.calculator.kpts2sizeandoffsets
The k-point coordinates can also be provided explicitly,
as a (N x 3) array with the scaled coordinates (relative
to the reciprocal unit cell vectors). Each of the N k-points
will be given equal weight.
---------
Additional object (to be set by function embed)
pcpot: PointCharge object
An external point charge potential (only in qmmm)
"""
if 'DFTB_PREFIX' in os.environ:
self.slako_dir = os.environ['DFTB_PREFIX'].rstrip('/') + '/'
else:
self.slako_dir = './'
# to run Dftb as energy and force calculator use
# Driver_MaxSteps=0,
if run_manyDftb_steps:
# minimisation of molecular dynamics is run by native DFTB+
self.default_parameters = dict(
Hamiltonian_='DFTB',
Hamiltonian_SlaterKosterFiles_='Type2FileNames',
Hamiltonian_SlaterKosterFiles_Prefix=self.slako_dir,
Hamiltonian_SlaterKosterFiles_Separator='"-"',
Hamiltonian_SlaterKosterFiles_Suffix='".skf"',
Hamiltonian_MaxAngularMomentum_='')
else:
# using ase to get forces and energy only
# (single point calculation)
self.default_parameters = dict(
Hamiltonian_='DFTB',
Driver_='ConjugateGradient',
Driver_MaxForceComponent='1E-4',
Driver_MaxSteps=0,
Hamiltonian_SlaterKosterFiles_='Type2FileNames',
Hamiltonian_SlaterKosterFiles_Prefix=self.slako_dir,
Hamiltonian_SlaterKosterFiles_Separator='"-"',
Hamiltonian_SlaterKosterFiles_Suffix='".skf"',
Hamiltonian_MaxAngularMomentum_='')
self.pcpot = None
self.lines = None
self.atoms = None
self.atoms_input = None
self.outfilename = 'dftb.out'
FileIOCalculator.__init__(self, restart, ignore_bad_restart_file,
label, atoms,
**kwargs)
# Determine number of spin channels
try:
entry = kwargs['Hamiltonian_SpinPolarisation']
spinpol = 'colinear' in entry.lower()
except KeyError:
spinpol = False
self.nspin = 2 if spinpol else 1
# kpoint stuff by ase
self.kpts = kpts
self.kpts_coord = None
if self.kpts is not None:
initkey = 'Hamiltonian_KPointsAndWeights'
mp_mesh = None
offsets = None
if isinstance(self.kpts, dict):
if 'path' in self.kpts:
# kpts is path in Brillouin zone
self.parameters[initkey + '_'] = 'Klines '
self.kpts_coord = kpts2ndarray(self.kpts, atoms=atoms)
else:
# kpts is (implicit) definition of
# Monkhorst-Pack grid
self.parameters[initkey + '_'] = 'SupercellFolding '
mp_mesh, offsets = kpts2sizeandoffsets(atoms=atoms,
**self.kpts)
elif np.array(self.kpts).ndim == 1:
# kpts is Monkhorst-Pack grid
self.parameters[initkey + '_'] = 'SupercellFolding '
mp_mesh = self.kpts
offsets = [0.] * 3
elif np.array(self.kpts).ndim == 2:
# kpts is (N x 3) list/array of k-point coordinates
# each will be given equal weight
self.parameters[initkey + '_'] = ''
self.kpts_coord = np.array(self.kpts)
else:
raise ValueError('Illegal kpts definition:' + str(self.kpts))
if mp_mesh is not None:
eps = 1e-10
for i in range(3):
key = initkey + '_empty%03d' % i
val = [mp_mesh[i] if j == i else 0 for j in range(3)]
self.parameters[key] = ' '.join(map(str, val))
offsets[i] *= mp_mesh[i]
assert abs(offsets[i]) < eps or abs(offsets[i] - 0.5) < eps
# DFTB+ uses a different offset convention, where
# the k-point mesh is already Gamma-centered prior
# to the addition of any offsets
if mp_mesh[i] % 2 == 0:
offsets[i] += 0.5
key = initkey + '_empty%03d' % 3
self.parameters[key] = ' '.join(map(str, offsets))
elif self.kpts_coord is not None:
for i, c in enumerate(self.kpts_coord):
key = initkey + '_empty%09d' % i
c_str = ' '.join(map(str, c))
if 'Klines' in self.parameters[initkey + '_']:
c_str = '1 ' + c_str
else:
c_str += ' 1.0'
self.parameters[key] = c_str
