def term_acceptance_function(expansion_term):
variables = expansion_term.get_active_variables()
if not expansion_term.is_pure_type('strain')
#remove all terms with in-plane strain variables in them - these are fixed to 0 for (100) epitaxy
for variable in variables:
if variable.type_string == 'strain' and variable.index in [0, 1, 5]:
return False
#assume no forces or stresses on the cell
if expansion_term.order == 1:
return False
#only expand to second order w.r.t. strain
if expansion_term.is_pure_type('strain') and expansion_term.order > 2:
return False
#for perovskite structure under arbitrary homogeneous strain, displacement terms are centrosymmetric
if expansion_term.is_centrosymmetric():
return False
#only go to fourth order in single variable dsiplacement terms - don't do fourth order cross terms
if expansion_term.order == 4 and not expansion_term.has_single_variable():
return False
return True
taylor_expansion = TaylorExpansion(variables_list=variables, term_acceptance_function=term_acceptance_function)
print
print "Number of terms:", len(taylor_expansion)
print '\n\t\t',
print taylor_expansion
print '\n'*3
base_path = "./"
perturbation_magnitudes_dictionary = {'strain': 0.01, 'displacement': 0.2}
a = 3.79
Nx = 1
Ny = 1
Nz = 1
vasp_run_inputs_dictionary = {
'kpoint_scheme': 'Monkhorst',
'kpoint_subdivisions_list': [8, 8, 8],
'encut': 900,
'addgrid': True
}
relaxation_input_dictionary= {
'external_relaxation_count': 3,
'isif': [6],
'kpoint_schemes_list': [vasp_run_inputs_dictionary['kpoint_scheme']],
'kpoint_subdivisions_lists': [vasp_run_inputs_dictionary['kpoint_subdivisions_list']],
'ediff': [0.00001, 1e-7, 1e-9],
'encut': [vasp_run_inputs_dictionary['encut']],
'submission_script_modification_keys_list': ['100'],
'lwave': [True]
}
initial_structure=Perovskite(supercell_dimensions=[Nx, Ny, Nz], lattice=[[a*Nx, 0.0, 0.0], [0.0, a*Ny, 0.0], [0.0, 0.0, a*Nz*1.02]], species_list=['Sr', 'Ti', 'O'])
relaxation = VaspRelaxation(path=Path.join(base_path, 'relaxation'), initial_structure=initial_structure, input_dictionary=relaxation_input_dictionary)
if not relaxation.complete:
relaxation.update()
else:
relaxed_structure = relaxation.final_structure
force_calculation_path = Path.join(base_path, 'dfpt_force_calculation')
kpoints = Kpoints(scheme_string=vasp_run_inputs_dictionary['kpoint_scheme'], subdivisions_list=vasp_run_inputs_dictionary['kpoint_subdivisions_list'])
incar = IncarMaker.get_dfpt_hessian_incar({'encut': vasp_run_inputs_dictionary['encut']})
input_set = VaspInputSet(relaxed_structure, kpoints, incar, auto_change_lreal=False, auto_change_npar=False)
dfpt_force_run = VaspRun(path=force_calculation_path, input_set=input_set)
if not dfpt_force_run.complete:
dfpt_force_run.update()
else:
hessian = Hessian(dfpt_force_run.outcar)
eigen_structure = EigenStructure(reference_structure=relaxed_structure, hessian=hessian)
eigen_structure.print_eigen_components()
de_path = Path.join(base_path, 'term_coefficient_calculations')
derivative_evaluator = DerivativeEvaluator(path=de_path, reference_structure=relaxed_structure, hessian=hessian, taylor_expansion=taylor_expansion,
reference_completed_vasp_relaxation_run=relaxation, vasp_run_inputs_dictionary=vasp_run_inputs_dictionary, perturbation_magnitudes_dictionary=perturbation_magnitudes_dictionary)
derivative_evaluator.update()
print derivative_evaluator.taylor_expansion
force_calculation_path = Path.join(base_path, 'dfpt_force_calculation') kpoints = Kpoints(scheme_string=kpoint_scheme, subdivisions_list=kpoint_subdivisions_list) incar = IncarMaker.get_dfpt_hessian_incar(dfpt_incar_settings) input_set = VaspInputSet(relaxed_structure, kpoints, incar, auto_change_lreal=False, auto_change_npar=False) dfpt_force_run = VaspRun(path=force_calculation_path, input_set=input_set) if not dfpt_force_run.complete: dfpt_force_run.update() else: hessian = Hessian(dfpt_force_run.outcar) #hessian.print_eigen_components() hessian.print_eigenvalues() guessed_minima_data_path = Path.join(base_path, 'guessed_chromosomes') minima_path = Path.join(base_path, 'minima_tests') if Path.exists(guessed_minima_data_path): minima_file = File(guessed_minima_data_path) eigen_chromosome_energy_pairs_list = [] #[[predicted_energy_difference_1, [e1, e2, e3, e4, ...]], [predicted_energy_difference_2, [e1, ...]]]
'kpoint_subdivisions_list'])
incar = IncarMaker.get_dfpt_hessian_incar(dfpt_incar_settings)
input_set = VaspInputSet(relaxed_structure,
kpoints,
incar,
auto_change_lreal=False,
auto_change_npar=False)
dfpt_force_run = VaspRun(path=force_calculation_path, input_set=input_set)
if not dfpt_force_run.complete:
dfpt_force_run.update()
else:
hessian = Hessian(dfpt_force_run.outcar)
hessian.print_eigen_components()
derivative_evaluator_list = []
for i in range(len(displacement_magnitudes_list)):
# perturbation_magnitudes_dictionary = {'strain': 0.01, 'displacement': displacement_magnitudes_list[i]}
perturbation_magnitudes_dictionary = {
'strain': 0.01,
'displacement': displacement_magnitudes_list[i]
}
de_path = Path.join(
base_path, 'term_coefficient_calculations_' +
str(displacement_magnitudes_list[i]))
derivative_evaluator = DerivativeEvaluator(
Nz = 1
relax_input_dictionary = {
'external_relaxation_count': 0,
'kpoint_schemes_list': ['Monkhorst'],
'kpoint_subdivisions_lists': [[6, 6, 6]],
'submission_node_count_list': [1],
'ediff': [0.000001],
'encut': [800]
}
supercell_dimensions = [Nx, Ny, Nz]
base_path = './'
outcar = Outcar(Path.join(base_path, 'OUTCAR_small_refined'))
hessian = Hessian(outcar)
reference_structure = Perovskite(supercell_dimensions=[Nx, Ny, Nz],
lattice=[[a * Nx, 0.0,
0.0], [0.0, a * Ny, 0.0],
[0.0, 0.0, a * Nz]],
species_list=['Sr', 'Ti', 'O'])
# print eigen_structure
# print eigen_structure.eigen_components_list[component_index]
# eigen_structure.print_eigen_components()
component_indices = range(3 * reference_structure.site_count)
stored_energy = None
increment = 0.05
def run_misfit_strain(path, misfit_strain, input_dictionary,
initial_relaxation_input_dictionary, dfpt_incar_settings,
derivative_evaluation_vasp_run_inputs_dictionary,
minima_relaxation_input_dictionary,
epitaxial_relaxation_input_dictionary):
Path.make(path)
guessed_minima_data_path = Path.join(path, 'guessed_chromosomes')
species_list = input_dictionary['species_list']
reference_lattice_constant = input_dictionary['reference_lattice_constant']
Nx = input_dictionary['supercell_dimensions_list'][0]
Ny = input_dictionary['supercell_dimensions_list'][1]
Nz = input_dictionary['supercell_dimensions_list'][2]
displacement_finite_differences_step_size = input_dictionary[
'displacement_finite_differences_step_size']
perturbation_magnitudes_dictionary = input_dictionary[
'perturbation_magnitudes_dictionary']
a = reference_lattice_constant * (1.0 + misfit_strain)
initial_structure = Perovskite(
supercell_dimensions=[Nx, Ny, Nz],
lattice=[[a * Nx, 0.0, 0.0], [0.0, a * Ny, 0.0],
[
0.0, 0.0, reference_lattice_constant * Nz *
(1.0 + 0.3 * (1.0 - (a / reference_lattice_constant)))
]],
species_list=species_list)
relaxation = VaspRelaxation(
path=Path.join(path, 'relaxation'),
initial_structure=initial_structure,
input_dictionary=initial_relaxation_input_dictionary)
if not relaxation.complete:
relaxation.update()
return False
relaxed_structure = relaxation.final_structure
relaxed_structure_path = Path.join(path, 'output_relaxed_structure')
relaxed_structure.to_poscar_file_path(relaxed_structure_path)
force_calculation_path = Path.join(path, 'dfpt_force_calculation')
kpoints = Kpoints(scheme_string=kpoint_scheme,
subdivisions_list=kpoint_subdivisions_list)
incar = IncarMaker.get_dfpt_hessian_incar(dfpt_incar_settings)
input_set = VaspInputSet(relaxed_structure,
kpoints,
incar,
auto_change_lreal=False,
auto_change_npar=False)
input_set.incar['lepsilon'] = True
dfpt_force_run = VaspRun(path=force_calculation_path, input_set=input_set)
if not dfpt_force_run.complete:
dfpt_force_run.update()
return False
hessian = Hessian(dfpt_force_run.outcar)
if input_dictionary['write_hessian_data']:
hessian.print_eigenvalues_to_file(
Path.join(path, 'output_eigen_values'))
hessian.print_eigen_components_to_file(
Path.join(path, 'output_eigen_components'))
hessian.print_mode_effective_charge_vectors_to_file(
Path.join(path, 'output_mode_effective_charge_vectors'),
relaxed_structure)
eigen_structure = EigenStructure(reference_structure=relaxed_structure,
hessian=hessian)
mode_structures_path = Path.join(path, 'mode_rendered_structures')
Path.make(mode_structures_path)
mode_charge_file = File(
Path.join(path, 'output_mode_effective_charge_vectors'))
sorted_eigen_pairs = hessian.get_sorted_hessian_eigen_pairs_list()
for i, structure in enumerate(
eigen_structure.get_mode_distorted_structures_list(
amplitude=0.6)):
if i > 30:
break
structure.to_poscar_file_path(
Path.join(
mode_structures_path, 'u' + str(i + 1) + '_' +
str(round(sorted_eigen_pairs[i].eigenvalue, 2)) + '.vasp'))
structure.lattice = Lattice([[8.0, 0.0, 0.0], [0.0, 8.0, 0.0],
[0.0, 0.0, 8.0]])
mode_charge_file[i] += ' ' + structure.get_spacegroup_string(
symprec=0.2) + ' ' + structure.get_spacegroup_string(
symprec=0.1) + ' ' + structure.get_spacegroup_string(
symprec=0.001)
mode_charge_file.write_to_path()
#sys.exit()
################################################### random structure searcher
if True:
rand_path = Path.join(path, 'random_trials')
Path.make(rand_path)
num_guesses = 1
num_modes = 12
max_amplitude = 0.6
if misfit_strain == 0.02:
eigen_structure = EigenStructure(
reference_structure=relaxed_structure, hessian=hessian)
for i in range(num_guesses):
trial_path = Path.join(rand_path, str(i))
if not Path.exists(trial_path):
initial_structure_trial = eigen_structure.get_random_structure(
mode_count_cutoff=num_modes,
max_amplitude=max_amplitude)
trial_relaxation = VaspRelaxation(
path=trial_path,
initial_structure=initial_structure_trial,
input_dictionary=minima_relaxation_input_dictionary)
else:
trial_relaxation = VaspRelaxation(path=trial_path)
print "Updating random trial relaxation at " + trial_relaxation.path + " Status is " + trial_relaxation.get_status_string(
)
trial_relaxation.update()
if trial_relaxation.complete:
print "Trial " + str(i)
print trial_relaxation.get_data_dictionary()
return None
###################################################
if not Path.exists(guessed_minima_data_path):
variable_specialty_points_dictionary = input_dictionary[
'variable_specialty_points_dictionary_set'][
misfit_strain] if input_dictionary.has_key(
misfit_strain) else {}
derivative_evaluation_path = Path.join(
path, 'expansion_coefficient_calculations')
derivative_evaluator = DerivativeEvaluator(
path=derivative_evaluation_path,
reference_structure=relaxed_structure,
hessian=hessian,
reference_completed_vasp_relaxation_run=relaxation,
vasp_run_inputs_dictionary=
derivative_evaluation_vasp_run_inputs_dictionary,
perturbation_magnitudes_dictionary=
perturbation_magnitudes_dictionary,
displacement_finite_differences_step_size=
displacement_finite_differences_step_size,
status_file_path=Path.join(path, 'output_derivative_plot_data'),
variable_specialty_points_dictionary=
variable_specialty_points_dictionary,
max_displacement_variables=input_dictionary[
'max_displacement_variables'])
derivative_evaluator.update()
else:
minima_path = Path.join(path, 'minima_relaxations')
minima_relaxer = MinimaRelaxer(
path=minima_path,
reference_structure=relaxed_structure,
reference_completed_vasp_relaxation_run=relaxation,
hessian=hessian,
vasp_relaxation_inputs_dictionary=
minima_relaxation_input_dictionary,
eigen_chromosome_energy_pairs_file_path=guessed_minima_data_path,
log_base_path=path,
max_minima=input_dictionary['max_minima'])
minima_relaxer.update()
minima_relaxer.print_status_to_file(
Path.join(path, 'output_minima_relaxations_status'))
if minima_relaxer.complete:
print "Minima relaxer complete: sorting the relaxations to find the lowest energy structure."
#minima_relaxer.print_selected_uniques_to_file(file_path=Path.join(path, 'output_selected_unique_minima_relaxations'))
sorted_uniques = minima_relaxer.get_sorted_unique_relaxation_data_list(
)
return sorted_uniques
def run_misfit_strain(path, misfit_strain, input_dictionary,
initial_relaxation_input_dictionary, dfpt_incar_settings,
derivative_evaluation_vasp_run_inputs_dictionary,
minima_relaxation_input_dictionary,
epitaxial_relaxation_input_dictionary):
Path.make(path)
species_list = input_dictionary['species_list']
reference_lattice_constant = input_dictionary['reference_lattice_constant']
Nx = input_dictionary['supercell_dimensions_list'][0]
Ny = input_dictionary['supercell_dimensions_list'][1]
Nz = input_dictionary['supercell_dimensions_list'][2]
displacement_finite_differrences_step_size = input_dictionary[
'displacement_finite_differrences_step_size']
perturbation_magnitudes_dictionary = input_dictionary[
'perturbation_magnitudes_dictionary']
a = reference_lattice_constant * (1.0 + misfit_strain)
initial_structure = Perovskite(
supercell_dimensions=[Nx, Ny, Nz],
lattice=[[a * Nx, 0.0, 0.0], [0.0, a * Ny, 0.0],
[
0.0, 0.0, reference_lattice_constant * Nz *
(1.0 + 0.3 * (1.0 - (a / reference_lattice_constant)))
]],
species_list=species_list)
relaxation = VaspRelaxation(
path=Path.join(path, 'relaxation'),
initial_structure=initial_structure,
input_dictionary=initial_relaxation_input_dictionary)
if not relaxation.complete:
relaxation.update()
return False
relaxed_structure = relaxation.final_structure
relaxed_structure_path = Path.join(path, 'output_relaxed_structure')
relaxed_structure.to_poscar_file_path(relaxed_structure_path)
force_calculation_path = Path.join(path, 'dfpt_force_calculation')
kpoints = Kpoints(scheme_string=kpoint_scheme,
subdivisions_list=kpoint_subdivisions_list)
incar = IncarMaker.get_dfpt_hessian_incar(dfpt_incar_settings)
input_set = VaspInputSet(relaxed_structure,
kpoints,
incar,
auto_change_lreal=False,
auto_change_npar=False)
dfpt_force_run = VaspRun(path=force_calculation_path, input_set=input_set)
if not dfpt_force_run.complete:
dfpt_force_run.update()
return False
hessian = Hessian(dfpt_force_run.outcar)
hessian.print_eigenvalues_to_file(Path.join(path, 'output_eigen_values'))
hessian.print_eigen_components_to_file(
Path.join(path, 'output_eigen_components'))
variable_specialty_points_dictionary = input_dictionary[
'variable_specialty_points_dictionary_set'][
misfit_strain] if input_dictionary.has_key(misfit_strain) else {}
derivative_evaluation_path = Path.join(
path, 'expansion_coefficient_calculations')
derivative_evaluator = DerivativeEvaluator(
path=derivative_evaluation_path,
reference_structure=relaxed_structure,
hessian=hessian,
reference_completed_vasp_relaxation_run=relaxation,
vasp_run_inputs_dictionary=
derivative_evaluation_vasp_run_inputs_dictionary,
perturbation_magnitudes_dictionary=perturbation_magnitudes_dictionary,
displacement_finite_differrences_step_size=
displacement_finite_differrences_step_size,
status_file_path=Path.join(path, 'output_derivative_plot_data'),
variable_specialty_points_dictionary=
variable_specialty_points_dictionary)
derivative_evaluator.update()
guessed_minima_data_path = Path.join(path, 'guessed_chromosomes')
minima_path = Path.join(path, 'minima_relaxations')
if Path.exists(guessed_minima_data_path):
minima_relaxer = MinimaRelaxer(
path=minima_path,
reference_structure=relaxed_structure,
reference_completed_vasp_relaxation_run=relaxation,
hessian=hessian,
vasp_relaxation_inputs_dictionary=
minima_relaxation_input_dictionary,
eigen_chromosome_energy_pairs_file_path=guessed_minima_data_path)
minima_relaxer.update()
minima_relaxer.print_status_to_file(
Path.join(path, 'output_minima_relaxations_status'))
if minima_relaxer.complete:
minima_relaxer.print_selected_uniques_to_file(file_path=Path.join(
path, 'output_selected_unique_minima_relaxations'))
sorted_uniques = minima_relaxer.get_sorted_unique_relaxation_data_list(
)
return sorted_uniques
'encut': 400,
'ediff': 1e-4,
'lreal': False, #set based on system size if lreal key is not present,
'addgrid': True,
'nsw': 1,
'npar': 'Remove',
}
dfpt_force_run = VaspCalculationGenerator(vasp_calculation_input_dictionary)
dfpt_force_run.update()
if not dfpt_force_run.complete:
sys.exit()
hessian = Hessian(dfpt_force_run.outcar)
if input_dictionary['write_hessian_data']:
hessian.print_eigenvalues_to_file(Path.join(path, 'output_eigen_values'))
hessian.print_eigen_components_to_file(
Path.join(path, 'output_eigen_components'))
hessian.print_mode_effective_charge_vectors_to_file(
Path.join(path, 'output_mode_effective_charge_vectors'),
relaxed_structure)
eigen_structure = EigenStructure(reference_structure=relaxed_structure,
hessian=hessian)
mode_structures_path = Path.join(path, 'mode_rendered_structures')
Path.make(mode_structures_path)