def test_is_collinear(self):
magmoms_list = [[0, 0, 0], [1, 1, 1], [[0, 0, 0], [0, 0, 0], [0, 0,
0]],
[[0, 0, 1], [0, 0, 1], [0, 0, 1]],
[[0, 0, -1], [0, 0, 1], [0, 0, 1]],
[[2, 2, 2], [-2, -2, -2], [2, 2, 2]]]
for magmoms in magmoms_list:
self.assertEqual(Magmom.are_collinear(magmoms), True)
ncl_magmoms = [[[0, 0, 1], [0, 0, 1], [1, 2, 3]]]
self.assertEqual(Magmom.are_collinear(ncl_magmoms), False)
def test_is_collinear(self):
magmoms_list = [[0, 0, 0],
[1, 1, 1],
[[0, 0, 0], [0, 0, 0], [0, 0, 0]],
[[0, 0, 1], [0, 0, 1], [0, 0, 1]],
[[0, 0, -1], [0, 0, 1], [0, 0, 1]],
[[2, 2, 2], [-2, -2, -2], [2, 2, 2]]]
for magmoms in magmoms_list:
self.assertEqual(Magmom.are_collinear(magmoms), True)
ncl_magmoms = [[[0, 0, 1], [0, 0, 1], [1, 2, 3]]]
self.assertEqual(Magmom.are_collinear(ncl_magmoms), False)
def test_get_structures(self):
# incommensurate structures not currently supported
self.assertRaises(NotImplementedError, self.mcif_incom.get_structures)
# disordered magnetic structures not currently supported
self.assertRaises(NotImplementedError, self.mcif_disord.get_structures)
# taken from self.mcif_ncl, removing explicit magnetic symmops
# so that MagneticSymmetryGroup() has to be invoked
magcifstr = """
data_5yOhtAoR
_space_group.magn_name_BNS "P 4/m' b' m' "
_cell_length_a 7.1316
_cell_length_b 7.1316
_cell_length_c 4.0505
_cell_angle_alpha 90.00
_cell_angle_beta 90.00
_cell_angle_gamma 90.00
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Gd1 Gd 0.31746 0.81746 0.00000 1
B1 B 0.00000 0.00000 0.20290 1
B2 B 0.17590 0.03800 0.50000 1
B3 B 0.08670 0.58670 0.50000 1
loop_
_atom_site_moment_label
_atom_site_moment_crystalaxis_x
_atom_site_moment_crystalaxis_y
_atom_site_moment_crystalaxis_z
Gd1 5.05 5.05 0.0"""
s = self.mcif.get_structures(primitive=False)[0]
self.assertEqual(s.formula, "Ni32 O32")
self.assertTrue(Magmom.are_collinear(s.site_properties['magmom']))
# example with non-collinear spin
s_ncl = self.mcif_ncl.get_structures(primitive=False)[0]
s_ncl_from_msg = CifParser.from_string(magcifstr).get_structures(
primitive=False)[0]
self.assertEqual(s_ncl.formula, "Gd4 B16")
self.assertFalse(Magmom.are_collinear(s_ncl.site_properties['magmom']))
self.assertTrue(s_ncl.matches(s_ncl_from_msg))
def test_get_structures(self):
# incommensurate structures not currently supported
self.assertRaises(NotImplementedError, self.mcif_incom.get_structures)
# disordered magnetic structures not currently supported
self.assertRaises(NotImplementedError, self.mcif_disord.get_structures)
# taken from self.mcif_ncl, removing explicit magnetic symmops
# so that MagneticSymmetryGroup() has to be invoked
magcifstr = """
data_5yOhtAoR
_space_group.magn_name_BNS "P 4/m' b' m' "
_cell_length_a 7.1316
_cell_length_b 7.1316
_cell_length_c 4.0505
_cell_angle_alpha 90.00
_cell_angle_beta 90.00
_cell_angle_gamma 90.00
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Gd1 Gd 0.31746 0.81746 0.00000 1
B1 B 0.00000 0.00000 0.20290 1
B2 B 0.17590 0.03800 0.50000 1
B3 B 0.08670 0.58670 0.50000 1
loop_
_atom_site_moment_label
_atom_site_moment_crystalaxis_x
_atom_site_moment_crystalaxis_y
_atom_site_moment_crystalaxis_z
Gd1 5.05 5.05 0.0"""
s = self.mcif.get_structures(primitive=False)[0]
self.assertEqual(s.formula, "Ni32 O32")
self.assertTrue(Magmom.are_collinear(s.site_properties['magmom']))
# example with non-collinear spin
s_ncl = self.mcif_ncl.get_structures(primitive=False)[0]
s_ncl_from_msg = CifParser.from_string(magcifstr).get_structures(primitive=False)[0]
self.assertEqual(s_ncl.formula, "Gd4 B16")
self.assertFalse(Magmom.are_collinear(s_ncl.site_properties['magmom']))
self.assertTrue(s_ncl.matches(s_ncl_from_msg))
def check_and_force_collinear(mypatstructure, angle_tolerance=10.0):
"""Make sure the list of magmoms use the same spin axis by taking the
largest magnetic moments as a reference axis for collinear calculations
Parameters:
-----------
mypatstructure: Structure
structure object
angle_tolerance: float
the minimum angle to consider between the reference spin axis and
magnetic moments vector. Default=10.
Returns:
--------
all_true : boolean, if True the angle is within the threshold
"""
from pymatgen.electronic_structure.core import Magmom
from pymatgen.util.coord import get_angle
magmoms = mypatstructure.site_properties['magmom']
cif_moments, direction = Magmom.get_consistent_set_and_saxis(magmoms)
#print("direction", direction)
magmoms_ = np.empty([0,3])
for comp in magmoms:
magmoms_ = np.vstack([magmoms_, [comp[0], comp[1], comp[2]]])
#print("comp", comp[0], comp[1], comp[2])
# filter non zero moments
magmoms_nzr = [m for m in magmoms_ if abs(np.any(m))]
true_or_false = Magmom.are_collinear(magmoms)
#if true_or_false == False:
angles = np.empty([0, 1])
for m in magmoms_nzr:
angles = np.vstack([angles, get_angle(unit_vector(m), direction, units="degrees")])
#print("angles", angles)
store_check = []
for angle in angles:
store_check.append(check_angle_bool(angle, angle_tolerance))
all_true = np.allclose(True, store_check)
return all_true
def __init__(
self,
structure: Structure,
overwrite_magmom_mode: Union[OverwriteMagmomMode, str] = "none",
round_magmoms: bool = False,
detect_valences: bool = False,
make_primitive: bool = True,
default_magmoms: bool = None,
set_net_positive: bool = True,
threshold: float = 0.1,
):
"""
A class which provides a few helpful methods to analyze
collinear magnetic structures.
If magnetic moments are not defined, moments will be
taken either from default_magmoms.yaml (similar to the
default magmoms in MPRelaxSet, with a few extra definitions)
or from a specie:magmom dict provided by the default_magmoms
kwarg.
Input magmoms can be replaced using the 'overwrite_magmom_mode'
kwarg. This can be:
* "none" to do nothing,
* "respect_sign" which will overwrite existing magmoms with
those from default_magmoms but will keep sites with positive magmoms
positive, negative magmoms negative and zero magmoms zero,
* "respect_zeros", which will give a ferromagnetic structure
(all positive magmoms from default_magmoms) but still keep sites with
zero magmoms as zero,
* "replace_all" which will try to guess initial magmoms for
all sites in the structure irrespective of input structure
(this is most suitable for an initial DFT calculation),
* "replace_all_if_undefined" is the same as "replace_all" but only if
no magmoms are defined in input structure, otherwise it will respect
existing magmoms.
* "normalize" will normalize magmoms to unity, but will respect sign
(used for comparing orderings), magmoms < theshold will be set to zero
:param structure: Structure object
:param overwrite_magmom_mode (str): default "none"
:param round_magmoms (int or bool): will round input magmoms to
specified number of decimal places if integer is supplied, if set
to a float will try and group magmoms together using a kernel density
estimator of provided width, and extracting peaks of the estimator
:param detect_valences (bool): if True, will attempt to assign valences
to input structure
:param make_primitive (bool): if True, will transform to primitive
magnetic cell
:param default_magmoms (dict): (optional) dict specifying default magmoms
:param set_net_positive (bool): if True, will change sign of magnetic
moments such that the net magnetization is positive. Argument will be
ignored if mode "respect_sign" is used.
:param threshold (float): number (in Bohr magnetons) below which magmoms
will be rounded to zero, default of 0.1 can probably be increased for many
magnetic systems, depending on your application
"""
if default_magmoms:
self.default_magmoms = default_magmoms
else:
self.default_magmoms = DEFAULT_MAGMOMS
structure = structure.copy()
# check for disorder
if not structure.is_ordered:
raise NotImplementedError(
"Not implemented for disordered structures, "
"make ordered approximation first.")
if detect_valences:
trans = AutoOxiStateDecorationTransformation()
bva = BVAnalyzer()
try:
structure = trans.apply_transformation(structure)
except ValueError:
warnings.warn("Could not assign valences "
"for {}".format(
structure.composition.reduced_formula))
# check to see if structure has magnetic moments
# on site properties or species spin properties,
# prioritize site properties
has_magmoms = bool(structure.site_properties.get("magmom", False))
has_spin = False
for comp in structure.species_and_occu:
for sp, occu in comp.items():
if getattr(sp, "spin", False):
has_spin = True
# perform input sanitation ...
# rest of class will assume magnetic moments
# are stored on site properties:
# this is somewhat arbitrary, arguments can
# be made for both approaches
if has_magmoms and has_spin:
raise ValueError("Structure contains magnetic moments on both "
"magmom site properties and spin species "
"properties. This is ambiguous. Remove one or "
"the other.")
elif has_magmoms:
if None in structure.site_properties["magmom"]:
warnings.warn("Be careful with mixing types in your magmom "
"site properties. Any 'None' magmoms have been "
"replaced with zero.")
magmoms = [
m if m else 0 for m in structure.site_properties["magmom"]
]
elif has_spin:
magmoms = [getattr(sp, "spin", 0) for sp in structure.species]
structure.remove_spin()
else:
# no magmoms present, add zero magmoms for now
magmoms = [0] * len(structure)
# and overwrite magmoms with default magmoms later unless otherwise stated
if overwrite_magmom_mode == "replace_all_if_undefined":
overwrite_magmom_mode = "replace_all"
# test to see if input structure has collinear magmoms
self.is_collinear = Magmom.are_collinear(magmoms)
if not self.is_collinear:
warnings.warn(
"This class is not designed to be used with "
"non-collinear structures. If your structure is "
"only slightly non-collinear (e.g. canted) may still "
"give useful results, but use with caution.")
# this is for collinear structures only, make sure magmoms
# are all floats
magmoms = list(map(float, magmoms))
# set properties that should be done /before/ we process input magmoms
self.total_magmoms = sum(magmoms)
self.magnetization = sum(magmoms) / structure.volume
# round magmoms below threshold to zero
magmoms = [m if abs(m) > threshold else 0 for m in magmoms]
# overwrite existing magmoms with default_magmoms
if overwrite_magmom_mode not in (
"none",
"respect_sign",
"respect_zeros",
"replace_all",
"replace_all_if_undefined",
"normalize",
):
raise ValueError("Unsupported mode.")
for idx, site in enumerate(structure):
if site.species_string in self.default_magmoms:
# look for species first, e.g. Fe2+
default_magmom = self.default_magmoms[site.species_string]
elif (isinstance(site.specie, Specie)
and str(site.specie.element) in self.default_magmoms):
# look for element, e.g. Fe
default_magmom = self.default_magmoms[str(site.specie.element)]
else:
default_magmom = 0
# overwrite_magmom_mode = "respect_sign" will change magnitude of
# existing moments only, and keep zero magmoms as
# zero: it will keep the magnetic ordering intact
if overwrite_magmom_mode == "respect_sign":
set_net_positive = False
if magmoms[idx] > 0:
magmoms[idx] = default_magmom
elif magmoms[idx] < 0:
magmoms[idx] = -default_magmom
# overwrite_magmom_mode = "respect_zeros" will give a ferromagnetic
# structure but will keep zero magmoms as zero
elif overwrite_magmom_mode == "respect_zeros":
if magmoms[idx] != 0:
magmoms[idx] = default_magmom
# overwrite_magmom_mode = "replace_all" will ignore input magmoms
# and give a ferromagnetic structure with magnetic
# moments on *all* atoms it thinks could be magnetic
elif overwrite_magmom_mode == "replace_all":
magmoms[idx] = default_magmom
# overwrite_magmom_mode = "normalize" set magmoms magnitude to 1
elif overwrite_magmom_mode == "normalize":
if magmoms[idx] != 0:
magmoms[idx] = int(magmoms[idx] / abs(magmoms[idx]))
# round magmoms, used to smooth out computational data
magmoms = (self._round_magmoms(magmoms, round_magmoms)
if round_magmoms else magmoms)
if set_net_positive:
sign = np.sum(magmoms)
if sign < 0:
magmoms = -np.array(magmoms)
structure.add_site_property("magmom", magmoms)
if make_primitive:
structure = structure.get_primitive_structure(use_site_props=True)
self.structure = structure
def __init__(self, structure,
overwrite_magmom_mode="none",
round_magmoms=False,
detect_valences=False,
make_primitive=True,
default_magmoms=None,
threshold=0.1):
"""
A class which provides a few helpful methods to analyze
collinear magnetic structures.
If magnetic moments are not defined, moments will be
taken either from default_magmoms.yaml (similar to the
default magmoms in MPRelaxSet, with a few extra definitions)
or from a specie:magmom dict provided by the default_magmoms
kwarg.
Input magmoms can be replaced using the 'overwrite_magmom_mode'
kwarg. This can be:
* "none" to do nothing,
* "respect_sign" which will overwrite existing magmoms with
those from default_magmoms but will keep sites with positive magmoms
positive, negative magmoms negative and zero magmoms zero,
* "respect_zeros", which will give a ferromagnetic structure
(all positive magmoms from default_magmoms) but still keep sites with
zero magmoms as zero,
* "replace_all" which will try to guess initial magmoms for
all sites in the structure irrespective of input structure
(this is most suitable for an initial DFT calculation),
* "replace_all_if_undefined" is the same as "replace_all" but only if
no magmoms are defined in input structure, otherwise it will respect
existing magmoms.
:param structure: Structure object
:param overwrite_magmom_mode (str): default "none"
:param round_magmoms (int): will round input magmoms to
specified number of decimal places, suggest value of 1 or False
for typical DFT calculations depending on application
:param detect_valences (bool): if True, will attempt to assign valences
to input structure
:param make_primitive (bool): if True, will transform to primitive
magnetic cell
:param default_magmoms (dict): (optional) dict specifying default magmoms
:param threshold (float): number (in Bohr magnetons) below which magmoms
will be rounded to zero, default of 0.1 can probably be increased for many
magnetic systems, depending on your application
"""
if default_magmoms:
self.default_magmoms = default_magmoms
else:
self.default_magmoms = DEFAULT_MAGMOMS
structure = structure.copy()
# check for disorder
if not structure.is_ordered:
raise NotImplementedError("Not implemented for disordered structures, "
"make ordered approximation first.")
if detect_valences:
trans = AutoOxiStateDecorationTransformation()
bva = BVAnalyzer()
try:
structure = trans.apply_transformation(structure)
except ValueError:
warnings.warn("Could not assign valences "
"for {}".format(structure.composition.reduced_formula))
# check to see if structure has magnetic moments
# on site properties or species spin properties,
# prioritize site properties
has_magmoms = bool(structure.site_properties.get('magmom', False))
has_spin = False
for comp in structure.species_and_occu:
for sp, occu in comp.items():
if getattr(sp, 'spin', False):
has_spin = True
# perform input sanitation ...
# rest of class will assume magnetic moments
# are stored on site properties:
# this is somewhat arbitrary, arguments can
# be made for both approaches
if has_magmoms and has_spin:
raise ValueError("Structure contains magnetic moments on both "
"magmom site properties and spin species "
"properties. This is ambiguous. Remove one or "
"the other.")
elif has_magmoms:
if None in structure.site_properties['magmom']:
warnings.warn("Be careful with mixing types in your magmom "
"site properties. Any 'None' magmoms have been "
"replaced with zero.")
magmoms = [m if m else 0 for m in structure.site_properties['magmom']]
elif has_spin:
magmoms = [getattr(sp, 'spin', 0) for sp
in structure.species]
structure.remove_spin()
else:
# no magmoms present, add zero magmoms for now
magmoms = [0]*len(structure)
# and overwrite magmoms with default magmoms later unless otherwise stated
if overwrite_magmom_mode == "replace_all_if_undefined":
overwrite_magmom_mode = "replace_all"
# test to see if input structure has collinear magmoms
self.is_collinear = Magmom.are_collinear(magmoms)
if not self.is_collinear:
warnings.warn("This class is not designed to be used with "
"non-collinear structures. If your structure is "
"only slightly non-collinear (e.g. canted) may still "
"give useful results, but use with caution.")
# this is for collinear structures only, make sure magmoms
# are all floats
magmoms = list(map(float, magmoms))
# set properties that should be done /before/ we process input magmoms
self.total_magmoms = sum(magmoms)
self.magnetization = sum(magmoms)/structure.volume
# round magmoms below threshold to zero
magmoms = [m if abs(m) > threshold else 0 for m in magmoms]
# overwrite existing magmoms with default_magmoms
if overwrite_magmom_mode not in ("none", "respect_sign",
"respect_zeros", "replace_all",
"replace_all_if_undefined"):
raise ValueError("Unsupported mode.")
for idx, site in enumerate(structure):
if site.species_string in self.default_magmoms:
# look for species first, e.g. Fe2+
default_magmom = self.default_magmoms[site.species_string]
elif isinstance(site.specie, Specie) and \
str(site.specie.element) in self.default_magmoms:
# look for element, e.g. Fe
default_magmom = self.default_magmoms[str(site.specie.element)]
else:
default_magmom = 0
# overwrite_magmom_mode = "respect_sign" will change magnitude of
# existing moments only, and keep zero magmoms as
# zero: it will keep the magnetic ordering intact
if overwrite_magmom_mode == "respect_sign":
if magmoms[idx] > 0:
magmoms[idx] = default_magmom
elif magmoms[idx] < 0:
magmoms[idx] = -default_magmom
# overwrite_magmom_mode = "respect_zeros" will give a ferromagnetic
# structure but will keep zero magmoms as zero
elif overwrite_magmom_mode == "respect_zeros":
if magmoms[idx] != 0:
magmoms[idx] = default_magmom
# overwrite_magmom_mode = "replace_all" will ignore input magmoms
# and give a ferromagnetic structure with magnetic
# moments on *all* atoms it thinks could be magnetic
elif overwrite_magmom_mode == "replace_all":
magmoms[idx] = default_magmom
# round magmoms to specified number of
# decimal places, used to smooth out
# computational data
# TODO: be a bit smarter about rounding magmoms!
if round_magmoms:
magmoms = np.around(structure.site_properties['magmom'],
decimals=round_magmoms)
structure.add_site_property(magmoms)
structure.add_site_property('magmom', magmoms)
if make_primitive:
structure = structure.get_primitive_structure(use_site_props=True)
self.structure = structure
