def operate_magmom(self, magmom):
"""
Apply time reversal operator on the magnetic moment. Note that
magnetic moments transform as axial vectors, not polar vectors.
See 'Symmetry and magnetic structures', Rodríguez-Carvajal and
Bourée for a good discussion. DOI: 10.1051/epjconf/20122200010
Args:
magmom: Magnetic moment as electronic_structure.core.Magmom
class or as list or np array-like
Returns:
Magnetic moment after operator applied as Magmom class
"""
magmom = Magmom(magmom) # type casting to handle lists as input
transformed_moment = (self.apply_rotation_only(magmom.global_moment) *
np.linalg.det(self.rotation_matrix) *
self.time_reversal)
# retains input spin axis if different from default
return Magmom.from_global_moment_and_saxis(transformed_moment,
magmom.saxis)
def test_init(self):
# backwards compatibility for scalar-like magmoms
magmom = Magmom(2.0)
self.assertEqual(float(magmom), 2.0)
# backwards compatibility for list-like magmoms
magmom2 = Magmom([1, 2, 3])
self.assertEqual(list(magmom2), [1, 2, 3])
self.assertEqual(magmom2.global_moment.tolist(), [1, 2, 3])
# non-default saxis, normalized internally
magmom3 = Magmom([1, 2, 3], saxis=[1, 1, 1])
self.assertTrue(np.allclose(magmom3.saxis, [np.sqrt(1/3.)]*3))
# test construction from known global moment and desired, non-default saxis
magmom4 = Magmom.from_global_moment_and_saxis([1, 2, 3], saxis=[1, 0, 0])
self.assertTrue(np.allclose(magmom4.moment, [-3, 2, 1]))
# test global moments with non-default saxis
magmom5 = Magmom([-3, 2, 1], saxis=[1, 0, 0])
self.assertTrue(np.allclose(magmom5.global_moment, [1, 2, 3]))
def test_init(self):
# backwards compatibility for scalar-like magmoms
magmom = Magmom(2.0)
self.assertEqual(float(magmom), 2.0)
# backwards compatibility for list-like magmoms
magmom2 = Magmom([1, 2, 3])
self.assertEqual(list(magmom2), [1, 2, 3])
self.assertEqual(magmom2.global_moment.tolist(), [1, 2, 3])
# non-default saxis, normalized internally
magmom3 = Magmom([1, 2, 3], saxis=[1, 1, 1])
self.assertTrue(np.allclose(magmom3.saxis, [np.sqrt(1/3.)]*3))
# test construction from known global moment and desired, non-default saxis
magmom4 = Magmom.from_global_moment_and_saxis([1, 2, 3], saxis=[1, 0, 0])
self.assertTrue(np.allclose(magmom4.moment, [-3, 2, 1]))
# test global moments with non-default saxis
magmom5 = Magmom([-3, 2, 1], saxis=[1, 0, 0])
self.assertTrue(np.allclose(magmom5.global_moment, [1, 2, 3]))
def operate_magmom(self, magmom):
"""
Apply time reversal operator on the magnetic moment. Note that
magnetic moments transform as axial vectors, not polar vectors.
See 'Symmetry and magnetic structures', Rodríguez-Carvajal and
Bourée for a good discussion. DOI: 10.1051/epjconf/20122200010
Args:
magmom: Magnetic moment as electronic_structure.core.Magmom
class or as list or np array-like
Returns:
Magnetic moment after operator applied as Magmom class
"""
magmom = Magmom(magmom) # type casting to handle lists as input
transformed_moment = self.apply_rotation_only(magmom.global_moment) * \
np.linalg.det(self.rotation_matrix) * self.time_reversal
# retains input spin axis if different from default
return Magmom.from_global_moment_and_saxis(transformed_moment, magmom.saxis)
