import os
import copy
import subprocess
from math import pi, sqrt
import numpy as np
class ReadError(Exception):
pass
all_properties = ['energy', 'forces', 'stress', 'dipole',
'charges', 'magmom', 'magmoms']
all_changes = ['positions', 'numbers', 'cell', 'pbc',
'initial_charges', 'initial_magmoms']
# Recognized names of calculators sorted alphabetically:
names = ['abinit', 'aims', 'asap', 'castep', 'cp2k', 'dftb', 'eam', 'elk',
'emt', 'exciting', 'fleur', 'gaussian', 'gpaw', 'gromacs', 'hotbit',
'jacapo', 'lammps', 'lammpslib', 'lj', 'mopac', 'morse',
'nwchem', 'siesta', 'turbomole', 'vasp']
special = {'cp2k': 'CP2K',
'eam': 'EAM',
'elk': 'ELK',
'emt': 'EMT',
'fleur': 'FLEUR',
'lammps': 'LAMMPS',
'lammpslib': 'LAMMPSlib',
'lj': 'LennardJones',
'morse': 'MorsePotential',
'nwchem': 'NWChem'}
def get_calculator(name):
"""Return calculator class."""
if name == 'asap':
from asap3 import EMT as Calculator
elif name == 'gpaw':
from gpaw import GPAW as Calculator
elif name == 'hotbit':
from hotbit import Calculator
else:
classname = special.get(name, name.title())
module = __import__('ase.calculators.' + name, {}, None, [classname])
Calculator = getattr(module, classname)
return Calculator
def equal(a, b, tol=None):
"""ndarray-enabled comparison function."""
if isinstance(a, np.ndarray):
b = np.array(b)
if a.shape != b.shape:
return False
if tol is None:
return (a == b).all()
else:
return np.allclose(a, b, rtol=tol, atol=tol)
if isinstance(b, np.ndarray):
return equal(b, a, tol)
if tol is None:
return a == b
return abs(a - b) < tol * abs(b) + tol
def kptdensity2monkhorstpack(atoms, kptdensity=3.5, even=True):
"""Convert k-point density to Monkhorst-Pack grid size.
atoms: Atoms object
Contains unit cell and information about boundary conditions.
kptdensity: float
Required k-point density. Default value is 3.5 point per Ang^-1.
even: bool
Round up to even numbers.
"""
recipcell = atoms.get_reciprocal_cell()
kpts = []
for i in range(3):
if atoms.pbc[i]:
k = 2 * pi * sqrt((recipcell[i]**2).sum()) * kptdensity
if even:
kpts.append(2 * int(np.ceil(k / 2)))
else:
kpts.append(int(np.ceil(k)))
else:
kpts.append(1)
return np.array(kpts)
def kpts2mp(atoms, kpts, even=False):
if kpts is None:
return np.array([1, 1, 1])
if isinstance(kpts, (float, int)):
return kptdensity2monkhorstpack(atoms, kpts, even)
else:
return kpts
class Parameters(dict):
"""Dictionary for parameters.
Special feature: If param is a Parameters instance, then param.xc
is a shorthand for param['xc'].
"""
def __getattr__(self, key):
if key not in self:
return dict.__getattribute__(self, key)
return self[key]
def __setattr__(self, key, value):
self[key] = value
@classmethod
def read(cls, filename):
"""Read parameters from file."""
file = open(os.path.expanduser(filename))
parameters = cls(eval(file.read()))
file.close()
return parameters
def tostring(self):
keys = sorted(self.keys())
return 'dict(' + ',\n '.join(
'%s=%r' % (key, self[key]) for key in keys) + ')\n'
def write(self, filename):
file = open(filename, 'w')
file.write(self.tostring())
file.close()
[docs]class Calculator:
"""Base-class for all ASE calculators.
A calculator must raise NotImplementedError if asked for a
property that it can't calculate. So, if calculation of the
stress tensor has not been implemented, get_stress(atoms) should
raise NotImplementedError. This can be achieved simply by not
including the string 'stress' in the list implemented_properties
which is a class member. These are the names of the standard
properties: 'energy', 'forces', 'stress', 'dipole', 'charges',
'magmom' and 'magmoms'.
"""
implemented_properties = []
'Properties calculator can handle (energy, forces, ...)'
default_parameters = {}
'Default parameters'
def __init__(self, restart=None, ignore_bad_restart_file=False, label=None,
atoms=None, **kwargs):
"""Basic calculator implementation.
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
Name used for all files. May contain a directory.
atoms: Atoms object
Optional Atoms object to which the calculator will be
attached. When restarting, atoms will get its positions and
unit-cell updated from file.
"""
self.atoms = None # copy of atoms object from last calculation
self.results = {} # calculated properties (energy, forces, ...)
self.parameters = None # calculational parameters
if restart is not None:
try:
self.read(restart) # read parameters, atoms and results
except ReadError:
if ignore_bad_restart_file:
self.reset()
else:
raise
self.label = None
self.directory = None
self.prefix = None
self.set_label(label)
if self.parameters is None:
# Use default parameters if they were not read from file:
self.parameters = self.get_default_parameters()
if atoms is not None:
atoms.calc = self
if self.atoms is not None:
# Atoms were read from file. Update atoms:
if not (equal(atoms.numbers, self.atoms.numbers) and
(atoms.pbc == self.atoms.pbc).all()):
raise RuntimeError('Atoms not compatible with file')
atoms.positions = self.atoms.positions
atoms.cell = self.atoms.cell
self.set(**kwargs)
if not hasattr(self, 'name'):
self.name = self.__class__.__name__.lower()
[docs] def set_label(self, label):
"""Set label and convert label to directory and prefix.
Examples:
* label='abc': (directory='.', prefix='abc')
* label='dir1/abc': (directory='dir1', prefix='abc')
Calculators that must write results to files with fixed names
can overwrite this method so that the directory is set to all
of label."""
self.label = label
if label is None:
self.directory = None
self.prefix = None
else:
self.directory, self.prefix = os.path.split(label)
if self.directory == '':
self.directory = os.curdir
def get_default_parameters(self):
return Parameters(copy.deepcopy(self.default_parameters))
def todict(self):
default = self.get_default_parameters()
return dict((key, value)
for key, value in self.parameters.items()
if key not in default or value != default[key])
[docs] def reset(self):
"""Clear all information from old calculation."""
self.atoms = None
self.results = {}
[docs] def read(self, label):
"""Read atoms, parameters and calculated properties from output file.
Read result from self.label file. Raise ReadError if the file
is not there. If the file is corrupted or contains an error
message from the calculation, a ReadError should also be
raised. In case of succes, these attributes must set:
atoms: Atoms object
The state of the atoms from last calculation.
parameters: Parameters object
The parameter dictionary.
results: dict
Calculated properties like energy and forces.
The FileIOCalculator.read() method will typically read atoms
and parameters and get the results dict by calling the
read_results() method."""
self.set_label(label)
def get_atoms(self):
if self.atoms is None:
raise ValueError('Calculator has no atoms')
atoms = self.atoms.copy()
atoms.calc = self
return atoms
@classmethod
def read_atoms(cls, restart, **kwargs):
return cls(restart=restart, label=restart, **kwargs).get_atoms()
[docs] def set(self, **kwargs):
"""Set parameters like set(key1=value1, key2=value2, ...).
A dictionary containing the parameters that have been changed
is returned.
Subclasses must implement a set() method that will look at the
chaneged parameters and decide if a call to reset() is needed.
If the changed parameters are harmless, like a change in
verbosity, then there is no need to call reset().
The special keyword 'parameters' can be used to read
parameters from a file."""
if 'parameters' in kwargs:
filename = kwargs.pop('parameters')
parameters = Parameters.read(filename)
parameters.update(kwargs)
kwargs = parameters
changed_parameters = {}
for key, value in kwargs.items():
oldvalue = self.parameters.get(key)
if key not in self.parameters or not equal(value, oldvalue):
if isinstance(oldvalue, dict):
# Special treatment for dictionary parameters:
for name in value:
if name not in oldvalue:
raise KeyError(
'Unknown subparameter "%s" in '
'dictionary parameter "%s"' % (name, key))
oldvalue.update(value)
value = oldvalue
changed_parameters[key] = value
self.parameters[key] = value
return changed_parameters
[docs] def check_state(self, atoms, tol=1e-15):
"""Check for system changes since last calculation."""
if self.atoms is None:
system_changes = all_changes
else:
system_changes = []
if not equal(self.atoms.positions, atoms.positions, tol):
system_changes.append('positions')
if not equal(self.atoms.numbers, atoms.numbers):
system_changes.append('numbers')
if not equal(self.atoms.cell, atoms.cell, tol):
system_changes.append('cell')
if not equal(self.atoms.pbc, atoms.pbc):
system_changes.append('pbc')
if not equal(self.atoms.get_initial_magnetic_moments(),
atoms.get_initial_magnetic_moments(), tol):
system_changes.append('initial_magmoms')
if not equal(self.atoms.get_initial_charges(),
atoms.get_initial_charges(), tol):
system_changes.append('initial_charges')
return system_changes
def get_potential_energy(self, atoms=None, force_consistent=False):
energy = self.get_property('energy', atoms)
if force_consistent:
return self.results.get('free_energy', energy)
else:
return energy
def get_forces(self, atoms=None):
return self.get_property('forces', atoms)
def get_stress(self, atoms=None):
return self.get_property('stress', atoms)
def get_dipole_moment(self, atoms=None):
return self.get_property('dipole', atoms)
def get_charges(self, atoms=None):
return self.get_property('charges', atoms)
def get_magnetic_moment(self, atoms=None):
return self.get_property('magmom', atoms)
def get_magnetic_moments(self, atoms=None):
return self.get_property('magmoms', atoms)
def get_property(self, name, atoms=None, allow_calculation=True):
if name not in self.implemented_properties:
raise NotImplementedError
if atoms is None:
atoms = self.atoms
system_changes = []
else:
system_changes = self.check_state(atoms)
if system_changes:
self.reset()
if name not in self.results:
if not allow_calculation:
return None
try:
self.calculate(atoms, [name], system_changes)
except Exception:
self.reset()
raise
if name == 'magmom' and 'magmom' not in self.results:
return 0.0
if name == 'magmoms' and 'magmoms' not in self.results:
return np.zeros(len(atoms))
result = self.results[name]
if isinstance(result, np.ndarray):
result = result.copy()
return result
def calculation_required(self, atoms, properties):
system_changes = self.check_state(atoms)
if system_changes:
return True
for name in properties:
if name not in self.results:
return True
return False
[docs] def calculate(self, atoms=None, properties=['energy'],
system_changes=all_changes):
"""Do the calculation.
properties: list of str
List of what needs to be calculated. Can be any combination
of 'energy', 'forces', 'stress', 'dipole', 'charges', 'magmom'
and 'magmoms'.
system_changes: list of str
List of what has changed since last calculation. Can be
any combination of these five: 'positions', 'numbers', 'cell',
'pbc', 'initial_charges' and 'initial_magmoms'.
Subclasses need to implement this, but can ignore properties
and system_changes if they want. Calculated properties should
be inserted into results dictionary like shown in this dummy
example::
self.results = {'energy': 0.0,
'forces': np.zeros((len(atoms), 3)),
'stress': np.zeros(6),
'dipole': np.zeros(3),
'charges': np.zeros(len(atoms)),
'magmom': 0.0,
'magmoms': np.zeros(len(atoms))}
The subclass implementation should first call this
implementation to set the atoms attribute.
"""
if atoms is not None:
self.atoms = atoms.copy()
[docs] def calculate_numerical_forces(self, atoms, d=0.001):
"""Calculate numerical forces using finite difference.
All atoms will be displaced by +d and -d in all directions."""
from ase.calculators.test import numeric_force
return np.array([[numeric_force(atoms, a, i, d)
for i in range(3)] for a in range(len(atoms))])
def get_spin_polarized(self):
return False
[docs]class FileIOCalculator(Calculator):
"""Base class for calculators that write/read input/output files."""
command = None
'Command used to start calculation'
def __init__(self, restart=None, ignore_bad_restart_file=False,
label=None, atoms=None, command=None, **kwargs):
"""File-IO calculator.
command: str
Command used to start calculation.
"""
Calculator.__init__(self, restart, ignore_bad_restart_file, label,
atoms, **kwargs)
if command is not None:
self.command = command
else:
name = 'ASE_' + self.name.upper() + '_COMMAND'
self.command = os.environ.get(name, self.command)
def calculate(self, atoms=None, properties=['energy'],
system_changes=all_changes):
Calculator.calculate(self, atoms, properties, system_changes)
self.write_input(self.atoms, properties, system_changes)
if self.command is None:
raise RuntimeError('Please set $%s environment variable ' %
('ASE_' + self.name.upper() + '_COMMAND') +
'or supply the command keyword')
command = self.command.replace('PREFIX', self.prefix)
olddir = os.getcwd()
try:
os.chdir(self.directory)
errorcode = subprocess.call(command, shell=True)
finally:
os.chdir(olddir)
if errorcode:
raise RuntimeError('%s returned an error: %d' %
(self.name, errorcode))
self.read_results()
[docs] def read_results(self):
"""Read energy, forces, ... from output file(s)."""
pass