def test_kumagai(self):
gamma = 0.19357221
prec = 28
lattice = Lattice(
[[4.692882, -8.12831, 0.0], [4.692882, 8.12831, 0.0], [0.0, 0.0, 10.03391]]
)
# note that real/recip vector generation is not dependent on epsilon
g_vecs, _, r_vecs, _ = generate_R_and_G_vecs(
gamma, prec, lattice, 80.0 * np.identity(3)
)
# test real space summation (bigger for large epsilon)
kc_high_diel = KumagaiCorrection(80.0 * np.identity(3), gamma=gamma)
real_sum = kc_high_diel.get_real_summation(gamma, r_vecs[0])
self.assertAlmostEqual(real_sum, 0.00843104)
# test recip space summation (bigger for small epsilon)
kc_low_diel = KumagaiCorrection(0.1 * np.identity(3), gamma=gamma)
recip_sum = kc_low_diel.get_recip_summation(gamma, g_vecs[0], lattice.volume)
self.assertAlmostEqual(recip_sum, 0.31117099)
# test self interaction
si_corr = kc_low_diel.get_self_interaction(gamma)
self.assertAlmostEqual(si_corr, -0.54965249)
# test potenital shift interaction correction
ps_corr = kc_low_diel.get_potential_shift(gamma, lattice.volume)
self.assertAlmostEqual(ps_corr, -0.00871593)
# """Test Defect Entry approach to correction """
bulk_struc = Poscar.from_file(
os.path.join(PymatgenTest.TEST_FILES_DIR, "defect", "CONTCAR_bulk")
).structure
bulk_out = Outcar(os.path.join(PymatgenTest.TEST_FILES_DIR, "defect", "OUTCAR_bulk.gz"))
defect_out = Outcar(os.path.join(PymatgenTest.TEST_FILES_DIR, "defect", "OUTCAR_vac_Ga_-3.gz"))
epsilon = 18.118 * np.identity(3)
vac = Vacancy(bulk_struc, bulk_struc.sites[0], charge=-3)
defect_structure = vac.generate_defect_structure()
defect_frac_coords = [0.0, 0.0, 0.0]
parameters = {
"bulk_atomic_site_averages": bulk_out.electrostatic_potential,
"defect_atomic_site_averages": defect_out.electrostatic_potential,
"site_matching_indices": [[ind, ind - 1] for ind in range(len(bulk_struc))],
"initial_defect_structure": defect_structure,
"defect_frac_sc_coords": defect_frac_coords,
}
dentry = DefectEntry(vac, 0.0, parameters=parameters)
kc = KumagaiCorrection(epsilon)
kcorr = kc.get_correction(dentry)
self.assertAlmostEqual(kcorr["kumagai_electrostatic"], 0.88236299)
self.assertAlmostEqual(kcorr["kumagai_potential_alignment"], 2.09704862)
# test ES correction
high_diel_es_corr = kc_high_diel.perform_es_corr(gamma, prec, lattice, -3.0)
self.assertAlmostEqual(high_diel_es_corr, 0.25176240)
low_diel_es_corr = kc_low_diel.perform_es_corr(gamma, prec, lattice, -3.0)
self.assertAlmostEqual(low_diel_es_corr, 201.28810966)
# test pot correction
site_list = []
for bs_ind, ds_ind in dentry.parameters["site_matching_indices"]:
Vqb = -(
defect_out.electrostatic_potential[ds_ind]
- bulk_out.electrostatic_potential[bs_ind]
)
site_list.append([defect_structure[ds_ind], Vqb])
sampling_radius = dentry.parameters["kumagai_meta"]["sampling_radius"]
gamma = dentry.parameters["kumagai_meta"]["gamma"]
q = -3
g_vecs, _, r_vecs, _ = generate_R_and_G_vecs(
gamma, 28, defect_structure.lattice, np.identity(3)
)
high_diel_pot_corr = kc_high_diel.perform_pot_corr(
defect_structure,
defect_frac_coords,
site_list,
sampling_radius,
q,
r_vecs[0],
g_vecs[0],
gamma,
)
self.assertAlmostEqual(high_diel_pot_corr, 2.35840716)
low_diel_pot_corr = kc_low_diel.perform_pot_corr(
defect_structure,
defect_frac_coords,
site_list,
sampling_radius,
q,
r_vecs[0],
g_vecs[0],
gamma,
)
self.assertAlmostEqual(low_diel_pot_corr, -58.83598095)
# test the kumagai plotter
kcp = kc.plot()
self.assertTrue(kcp)
# check that uncertainty metadata exists
self.assertAlmostEqual(
set(kc.metadata["pot_corr_uncertainty_md"].keys()),
set(["number_sampled", "stats"]),
)
def get_kumagai_correction(structure_defect,structure_bulk,path_to_defect_outcar,path_to_bulk_outcar,dielectric_tensor,
charge,defect_type=None,defect_specie=None,defect_site=None,sampling_radius=None,gamma=None,
get_plot=False):
"""
Get Kumagai correction with Pymatgen.
Parameters
----------
structure_defect : (Structure)
Structure of defect.
structure_bulk : (Structure)
Bulk structure.
path_to_defect_outcar : (str)
Path to OUTCAR of defect calculation.
path_to_bulk_outcar : (str)
Path to OUTCAR of pure calculation.
dielectric_tensor : (array or float)
Dielectric tensor, if is a float a diagonal matrix is constructed.
charge : (int or float)
Charge of the defect.
defect_type : (str), optional
Type of defect ('Vacancy','Interstitial' or 'Substitution')
If None it's determined with defect_finder. The default is None.
defect_specie : (str), optional
Symbol of the defect specie.
If None it's determined with defect_finder. The default is None.
defect_site : (Site), optional
Site of defect. If None it's determined with defect_finder. The default is None.
sampling_radius (float): radius (in Angstrom) which sites must be outside
of to be included in the correction. Publication by Kumagai advises to
use Wigner-Seitz radius of defect supercell, so this is default value.
gamma (float): convergence parameter for gamma function.
Code will automatically determine this if set to None.
get_plot : (bool), optional
Get Matplotlib object with plot. The default is False.
Returns
-------
corr : (dict or tuple)
Dictionary with corrections, if get_plot is True a tuple with dict and plt object is returned.
"""
if not defect_site and not defect_type and not defect_specie:
defect_site, defect_type = defect_finder(structure_defect, structure_bulk)
defect_specie = defect_site.specie.symbol
site_matching_indices = []
for site in structure_defect:
site_in_str ,index_bulk = is_site_in_structure(site, structure_bulk)
if site_in_str:
site_matching_indices.append([index_bulk,structure_defect.index(site)])
else:
print(f'Warning in Kumagai corrections: Site {site} is not in bulk structure')
bulk_atomic_site_averages = Outcar(op.join(path_to_bulk_outcar,'OUTCAR')).read_avg_core_poten()[-1]
defect_atomic_site_averages = Outcar(op.join(path_to_defect_outcar,'OUTCAR')).read_avg_core_poten()[0]
defect_frac_sc_coords = defect_site.frac_coords
initial_defect_structure = structure_defect
parameters = {}
parameters['bulk_atomic_site_averages'] = bulk_atomic_site_averages
parameters['defect_atomic_site_averages'] = defect_atomic_site_averages
parameters['site_matching_indices'] = site_matching_indices
parameters['initial_defect_structure'] = initial_defect_structure
parameters['defect_frac_sc_coords'] = defect_frac_sc_coords
module = importlib.import_module("pymatgen.analysis.defects.core")
defect_class = getattr(module,defect_type)
defect = defect_class(structure_bulk, defect_site, charge=charge, multiplicity=None)
defect_entry = DefectEntry(defect,None,corrections=None,parameters=parameters)
kumagai = KumagaiCorrection(dielectric_tensor,sampling_radius,gamma)
kumagai_corrections = kumagai.get_correction(defect_entry)
if get_plot:
plt = kumagai.plot()
return kumagai_corrections , plt
else:
return kumagai_corrections
def get_correction_kumagai(defect_entry, epsilon, title=None, partflag='All'):
"""
Function to compute the Kumagai correction for each defect (modified freysoldt for anisotropic dielectric).
NOTE that bulk_init class must be pre-instantiated to use this function
Args:
defect_entry: DefectEntry object with the following
keys stored in defect.parameters:
required:
bulk_atomic_site_averages (list): list of bulk structure"s atomic site averaged ESPs * charge,
in same order as indices of bulk structure
note this is list given by VASP's OUTCAR (so it is multiplied by a test charge of -1)
defect_atomic_site_averages (list): list of defect structure"s atomic site averaged ESPs * charge,
in same order as indices of defect structure
note this is list given by VASP's OUTCAR (so it is multiplied by a test charge of -1)
site_matching_indices (list): list of corresponding site index values for
bulk and defect site structures EXCLUDING the defect site itself
(ex. [[bulk structure site index, defect structure"s corresponding site index], ... ]
initial_defect_structure (Structure): Pymatgen Structure object representing un-relaxed defect structure
defect_frac_sc_coords (array): Defect Position in fractional coordinates of the supercell
given in bulk_structure
optional:
gamma (float): Ewald parameter, Default is to determine it based on convergence of
brute summation tolerance
sampling_radius (float):r adius (in Angstrom) which sites must be outside of to be included
in the correction. Publication by Kumagai advises to use Wigner-Seitz radius of
defect supercell, so this is default value.
epsilon (float or 3x3 matrix): Dielectric constant for the structure
title: decides whether to plot electrostatic potential plots or not...
if None, no plot is printed, if a string,
then the plot will be saved using the string
partflag: four options for correction output:
'pc' for just point charge correction, or
'potalign' for just potalign correction, or
'All' for both (added together), or
'AllSplit' for individual parts split up (form is [PC, potterm, full])
"""
if partflag not in ['All', 'AllSplit', 'pc', 'potalign']:
print(
'{} is incorrect potalign type. Must be "All", "AllSplit", "pc", or '
'"potalign".'.format(partflag))
return
sampling_radius = defect_entry.parameters.get('sampling_radius', None)
gamma = defect_entry.parameters.get('gamma', None)
if not defect_entry.charge:
print('charge is zero so charge correction is zero')
return 0.
template_defect = defect_entry.copy()
corr_class = KumagaiCorrection(epsilon,
sampling_radius=sampling_radius,
gamma=gamma)
k_corr_summ = corr_class.get_correction(template_defect)
if title:
p = corr_class.plot(title="Kumagai", saved=False)
p.savefig(title + '_kumagaiplot.pdf', bbox_inches='tight')
if partflag in ['AllSplit', 'All']:
kumagai_val = np.sum(list(k_corr_summ.values()))
elif partflag == 'pc':
kumagai_val = k_corr_summ['kumagai_electrostatic']
elif partflag == 'potalign':
kumagai_val = k_corr_summ['kumagai_potential_alignment']
print('\n Final Kumagai correction is {}'.format(kumagai_val))
if partflag == 'AllSplit':
kumagai_val = [
k_corr_summ['kumagai_electrostatic'],
k_corr_summ['kumagai_potential_alignment'], kumagai_val
]
return kumagai_val
def test_kumagai(self):
gamma = 0.19357221
prec = 28
lattice = Lattice( [[ 4.692882, -8.12831 , 0.],
[ 4.692882, 8.12831 , 0.],
[ 0., 0., 10.03391 ]])
#note that real/recip vector generation is not dependent on epsilon
g_vecs, _, r_vecs, _ = generate_R_and_G_vecs( gamma, prec, lattice, 80. * np.identity(3))
#test real space summation (bigger for large epsilon)
kc_high_diel = KumagaiCorrection( 80. * np.identity(3), gamma=gamma)
real_sum = kc_high_diel.get_real_summation( gamma, r_vecs[0])
self.assertAlmostEqual( real_sum, 0.00843104)
#test recip space summation (bigger for small epsilon)
kc_low_diel = KumagaiCorrection( 0.1 * np.identity(3), gamma=gamma)
recip_sum = kc_low_diel.get_recip_summation( gamma, g_vecs[0], lattice.volume)
self.assertAlmostEqual( recip_sum, 0.31117099)
#test self interaction
si_corr = kc_low_diel.get_self_interaction( gamma)
self.assertAlmostEqual( si_corr, -0.54965249)
#test potenital shift interaction correction
ps_corr = kc_low_diel.get_potential_shift( gamma, lattice.volume)
self.assertAlmostEqual( ps_corr, -0.00871593)
# """Test Defect Entry approach to correction """
bulk_struc = Poscar.from_file(os.path.join( test_dir, 'defect', 'CONTCAR_bulk')).structure
bulk_out = Outcar( os.path.join( test_dir, 'defect', 'OUTCAR_bulk.gz'))
defect_out = Outcar( os.path.join( test_dir, 'defect', 'OUTCAR_vac_Ga_-3.gz'))
epsilon = 18.118 * np.identity(3)
vac = Vacancy(bulk_struc, bulk_struc.sites[0], charge=-3)
defect_structure = vac.generate_defect_structure()
defect_frac_coords = [0.,0.,0.]
parameters = {'bulk_atomic_site_averages': bulk_out.electrostatic_potential,
'defect_atomic_site_averages': defect_out.electrostatic_potential,
'site_matching_indices': [[ind, ind-1] for ind in range(len(bulk_struc))],
'initial_defect_structure': defect_structure,
'defect_frac_sc_coords': defect_frac_coords}
dentry = DefectEntry( vac, 0., parameters=parameters)
kc = KumagaiCorrection( epsilon)
kcorr = kc.get_correction( dentry)
self.assertAlmostEqual( kcorr['kumagai_electrostatic'], 0.88236299)
self.assertAlmostEqual( kcorr['kumagai_potential_alignment'], 2.09704862)
# test ES correction
high_diel_es_corr = kc_high_diel.perform_es_corr( gamma, prec, lattice, -3.)
self.assertAlmostEqual( high_diel_es_corr, 0.25176240)
low_diel_es_corr = kc_low_diel.perform_es_corr( gamma, prec, lattice, -3.)
self.assertAlmostEqual( low_diel_es_corr, 201.28810966)
# test pot correction
site_list = []
for bs_ind, ds_ind in dentry.parameters['site_matching_indices']:
Vqb = -(defect_out.electrostatic_potential[ds_ind] - bulk_out.electrostatic_potential[bs_ind])
site_list.append([defect_structure[ds_ind], Vqb])
sampling_radius = dentry.parameters["kumagai_meta"]["sampling_radius"]
gamma = dentry.parameters["kumagai_meta"]["gamma"]
q = -3
g_vecs, _, r_vecs, _ = generate_R_and_G_vecs( gamma, 28, defect_structure.lattice, np.identity(3))
high_diel_pot_corr = kc_high_diel.perform_pot_corr( defect_structure, defect_frac_coords,
site_list, sampling_radius, q,
r_vecs[0], g_vecs[0], gamma)
self.assertAlmostEqual( high_diel_pot_corr, 2.35840716)
low_diel_pot_corr = kc_low_diel.perform_pot_corr( defect_structure, defect_frac_coords,
site_list, sampling_radius, q,
r_vecs[0], g_vecs[0], gamma)
self.assertAlmostEqual( low_diel_pot_corr, -58.83598095)
#test the kumagai plotter
kcp = kc.plot()
self.assertTrue( kcp)
#check that uncertainty metadata exists
self.assertAlmostEqual(set(kc.metadata['pot_corr_uncertainty_md'].keys()), set(['number_sampled', 'stats']))