def __init__(self,
mag_species_spin,
order_parameter=0.5,
energy_model=SymmetryModel(),
**kwargs):
self.mag_species_spin = mag_species_spin
if order_parameter > 1 or order_parameter < 0:
raise ValueError('Order Parameter must lie between 0 and 1')
else:
self.order_parameter = order_parameter
self.energy_model = energy_model
self.kwargs = kwargs
def __init__(self,
mag_species_spin,
order_parameter=0.5,
energy_model=SymmetryModel(),
**kwargs):
"""
This transformation takes a structure and returns a list of collinear
magnetic orderings. For disordered structures, make an ordered
approximation first.
:param mag_species_spin: A mapping of elements/species to their
spin magnitudes, e.g. {"Fe3+": 5, "Mn3+": 4}
:param order_parameter (float or list): if float, a specifies a
global order parameter and can take values from 0.0 to 1.0
(e.g. 0.5 for antiferromagnetic or 1.0 for ferromagnetic), if
list has to be a list of
:class: `pymatgen.transformations.advanced_transformations.MagOrderParameterConstraint`
to specify more complicated orderings, see documentation for
MagOrderParameterConstraint more details on usage
:param energy_model: Energy model to rank the returned structures,
see :mod: `pymatgen.analysis.energy_models` for more information (note
that this is not necessarily a physical energy). By default, returned
structures use SymmetryModel() which ranks structures from most
symmetric to least.
:param kwargs: Additional kwargs that are passed to
:class:`EnumerateStructureTransformation` such as min_cell_size etc.
"""
# checking for sensible order_parameter values
if isinstance(order_parameter, float):
# convert to constraint format
order_parameter = [
MagOrderParameterConstraint(order_parameter=order_parameter,
species_constraints=list(
mag_species_spin.keys()))
]
elif isinstance(order_parameter, list):
ops = [
isinstance(item, MagOrderParameterConstraint)
for item in order_parameter
]
if not any(ops):
raise ValueError("Order parameter not correctly defined.")
else:
raise ValueError("Order parameter not correctly defined.")
self.mag_species_spin = mag_species_spin
# store order parameter constraints as dicts to save implementing
# to/from dict methods for MSONable compatibility
self.order_parameter = [op.as_dict() for op in order_parameter]
self.energy_model = energy_model
self.enum_kwargs = kwargs
def test_to_from_dict(self):
m = SymmetryModel(symprec=0.2)
d = m.as_dict()
o = SymmetryModel.from_dict(d)
self.assertIsInstance(o, SymmetryModel)
self.assertAlmostEqual(o.symprec, 0.2)
def test_get_energy(self):
m = SymmetryModel()
s2 = Structure.from_file(os.path.join(test_dir, "Li2O.cif"))
self.assertAlmostEqual(m.get_energy(s2), -225)
def test_to_from_dict(self):
m = SymmetryModel(symprec=0.2)
d = m.as_dict()
o = SymmetryModel.from_dict(d)
self.assertIsInstance(o, SymmetryModel)
self.assertAlmostEqual(o.symprec, 0.2)
def test_get_energy(self):
m = SymmetryModel()
s2 = Structure.from_file(os.path.join(PymatgenTest.TEST_FILES_DIR, "Li2O.cif"))
self.assertAlmostEqual(m.get_energy(s2), -225)
def test_get_energy(self):
m = SymmetryModel()
s2 = read_structure(os.path.join(test_dir, "Li2O.cif"))
self.assertEqual(m.get_energy(s2), -225)
def test_get_energy(self):
m = SymmetryModel()
s2 = Structure.from_file(os.path.join(test_dir, "Li2O.cif"))
self.assertAlmostEqual(m.get_energy(s2), -225)
def test_get_energy(self):
m = SymmetryModel()
s2 = read_structure(os.path.join(test_dir, "Li2O.cif"))
self.assertEqual(m.get_energy(s2), -225)
