Source code for dmft_tools.observables

################################################################################
#
# solid_dmft - A versatile python wrapper to perform DFT+DMFT calculations
#              utilizing the TRIQS software library
#
# Copyright (C) 2018-2020, ETH Zurich
# Copyright (C) 2021, The Simons Foundation
#      authors: A. Hampel, M. Merkel, and S. Beck
#
# solid_dmft is free software: you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
#
# solid_dmft is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
# PARTICULAR PURPOSE. See the GNU General Public License for more details.

# You should have received a copy of the GNU General Public License along with
# solid_dmft (in the file COPYING.txt in this directory). If not, see
# <http://www.gnu.org/licenses/>.
#
################################################################################
"""
Contains all functions related to the observables.
"""

# system
import os.path
import numpy as np

# triqs
import triqs.utility.mpi as mpi
from h5 import HDFArchive
from triqs.gf import Gf, MeshImTime
from triqs.atom_diag import trace_rho_op
from triqs.gf.descriptors import Fourier
from solid_dmft.dmft_tools import common

[docs] def prep_observables(h5_archive, sum_k): """ prepares the observable arrays and files for the DMFT calculation Parameters ---------- h5_archive: hdf archive instance hdf archive for calculation sum_k : SumK Object instances Returns ------- observables : dict observable array for calculation """ with HDFArchive(h5_archive, 'r') as ar: # determine number of impurities n_inequiv_shells = ar['dft_input']['n_inequiv_shells'] # check for previous iterations obs_prev = [] if 'observables' in ar['DMFT_results']: obs_prev = ar['DMFT_results']['observables'] # prepare observable dicts if len(obs_prev) > 0: observables = obs_prev else: observables = dict() observables['iteration'] = [] observables['mu'] = [] observables['E_tot'] = [] observables['E_bandcorr'] = [] observables['E_int'] = [[] for _ in range(n_inequiv_shells)] observables['E_corr_en'] = [] observables['E_dft'] = [] observables['E_DC'] = [[] for _ in range(n_inequiv_shells)] observables['orb_gb2'] = [{spin: [] for spin in sum_k.spin_block_names[sum_k.SO]} for _ in range(n_inequiv_shells)] observables['imp_gb2'] = [{spin: [] for spin in sum_k.spin_block_names[sum_k.SO]} for _ in range(n_inequiv_shells)] observables['orb_occ'] = [{spin: [] for spin in sum_k.spin_block_names[sum_k.SO]} for _ in range(n_inequiv_shells)] observables['orb_Z'] = [{spin: [] for spin in sum_k.spin_block_names[sum_k.SO]} for _ in range(n_inequiv_shells)] observables['imp_occ'] = [{spin: [] for spin in sum_k.spin_block_names[sum_k.SO]} for _ in range(n_inequiv_shells)] return observables
def _generate_header(general_params, sum_k): """ Generates the headers that are used in write_header_to_file. Returns a dict with {file_name: header_string} """ n_orb = common.get_n_orbitals(sum_k) header_energy_mask = ' | {:>10} | {:>10} {:>10} {:>10} {:>10}' header_energy = header_energy_mask.format('E_tot', 'E_DFT', 'E_bandcorr', 'E_int_imp', 'E_DC') headers = {} for iineq in range(sum_k.n_inequiv_shells): number_spaces = max(10*n_orb[iineq]['up'] + 3*(n_orb[iineq]['up']-1), 21) header_basic_mask = '{{:>3}} | {{:>10}} | {{:>{0}}} | {{:>{0}}} | {{:>17}}'.format(number_spaces) # If magnetic calculation is done create two obs files per imp if general_params['magnetic'] and sum_k.SO == 0: for spin in ('up', 'down'): file_name = 'observables_imp{}_{}.dat'.format(iineq, spin) headers[file_name] = header_basic_mask.format('it', 'mu', 'G(beta/2) per orbital', 'orbital occs '+spin, 'impurity occ '+spin) if general_params['calc_energies']: headers[file_name] += header_energy else: file_name = 'observables_imp{}.dat'.format(iineq) headers[file_name] = header_basic_mask.format('it', 'mu', 'G(beta/2) per orbital', 'orbital occs up+down', 'impurity occ') if general_params['calc_energies']: headers[file_name] += header_energy return headers
[docs] def write_header_to_file(general_params, sum_k): """ Writes the header to the observable files Parameters ---------- general_params : dict general parameters as a dict n_inequiv_shells : int number of impurities for calculations Returns ------- nothing """ headers = _generate_header(general_params, sum_k) for file_name, header in headers.items(): path = os.path.join(general_params['jobname'], file_name) with open(path, 'w') as obs_file: obs_file.write(header + '\n')
[docs] def add_dft_values_as_zeroth_iteration(observables, general_params, solver_type_per_imp, dft_mu, dft_energy, sum_k, G_loc_all_dft, shell_multiplicity): """ Calculates the DFT observables that should be written as the zeroth iteration. Parameters ---------- observables : observable arrays/dicts general_params : general parameters as a dict solver_type_per_imp : list of strings list of solver types for each impurity dft_mu : dft chemical potential sum_k : SumK Object instances G_loc_all_dft : Gloc from DFT for G(beta/2) shell_multiplicity : degeneracy of impurities Returns ------- observables: list of dicts """ dft_energy = 0.0 if dft_energy is None else dft_energy density_mat_dft = [G_loc_all_dft[iineq].density() for iineq in range(sum_k.n_inequiv_shells)] observables['iteration'].append(0) observables['mu'].append(float(dft_mu)) if general_params['calc_energies']: observables['E_bandcorr'].append(0.0) observables['E_corr_en'].append(0.0) observables['E_dft'].append(dft_energy) else: observables['E_bandcorr'].append('none') observables['E_corr_en'].append('none') observables['E_dft'].append('none') for iineq in range(sum_k.n_inequiv_shells): if general_params['calc_energies']: observables['E_int'][iineq].append(0.0) double_counting_energy = shell_multiplicity[iineq]*sum_k.dc_energ[sum_k.inequiv_to_corr[iineq]] if general_params['dc'] else 0.0 observables['E_DC'][iineq].append(double_counting_energy) else: observables['E_int'][iineq].append('none') observables['E_DC'][iineq].append('none') # Collect all occupation and G(beta/2) for spin up and down separately for spin in sum_k.spin_block_names[sum_k.SO]: g_beta_half_per_impurity = 0.0 g_beta_half_per_orbital = [] occupation_per_impurity = 0.0 occupation_per_orbital = [] Z_per_orbital = [] # iterate over all spin channels and add the to up or down # we need only the keys of the blocks, but sorted! Otherwise # orbitals will be mixed up_0 to down_0 etc. for spin_channel in sorted(sum_k.gf_struct_solver[iineq].keys()): if not spin in spin_channel: continue if solver_type_per_imp[iineq] == 'ftps': freq_mesh = np.array([w.value for w in G_loc_all_dft[iineq][spin_channel].mesh]) fermi_idx = abs(freq_mesh).argmin() gb2_averaged = G_loc_all_dft[iineq][spin_channel].data[fermi_idx].imag # Z is not defined without Sigma, adding 1 Z_per_orbital.extend( [1.0] * G_loc_all_dft[iineq][spin_channel].target_shape[0] ) else: # G(beta/2) mesh = MeshImTime(beta=general_params['beta'], S="Fermion", n_max=general_params['n_tau']) G_time = Gf(mesh=mesh, indices=G_loc_all_dft[iineq][spin_channel].indices) G_time << Fourier(G_loc_all_dft[iineq][spin_channel]) # since G(tau) has always 10001 values we are sampling +-10 values # hard coded around beta/2, for beta=40 this corresponds to approx +-0.05 mesh_mid = len(G_time.data) // 2 samp = 10 gg = G_time.data[mesh_mid-samp:mesh_mid+samp] gb2_averaged = np.mean(np.real(gg), axis=0) # Z is not defined without Sigma, adding 1 Z_per_orbital.extend( [1.0] * G_time.target_shape[0] ) g_beta_half_per_orbital.extend(np.diag(gb2_averaged)) g_beta_half_per_impurity += np.trace(gb2_averaged) # occupation per orbital den_mat = np.real(density_mat_dft[iineq][spin_channel]) occupation_per_orbital.extend(np.diag(den_mat)) occupation_per_impurity += np.trace(den_mat) # adding those values to the observable object observables['orb_gb2'][iineq][spin].append(np.array(g_beta_half_per_orbital)) observables['imp_gb2'][iineq][spin].append(g_beta_half_per_impurity) observables['orb_occ'][iineq][spin].append(np.array(occupation_per_orbital)) observables['imp_occ'][iineq][spin].append(occupation_per_impurity) observables['orb_Z'][iineq][spin].append(np.array(Z_per_orbital)) # for it 0 we just subtract E_DC from E_DFT if general_params['calc_energies']: observables['E_tot'].append(dft_energy - sum([dc_per_imp[0] for dc_per_imp in observables['E_DC']])) else: observables['E_tot'].append('none') return observables
[docs] def add_dmft_observables(observables, general_params, solver_params, map_imp_solver, solver_type_per_imp, dft_energy, it, solvers, h_int, previous_mu, sum_k, density_mat, shell_multiplicity, E_bandcorr): """ calculates the observables for given Input, I decided to calculate the observables not adhoc since it should be done only once by the master_node Parameters ---------- observables : observable arrays/dicts general_params : general parameters as a dict solver_params : solver parameters as a dict it : iteration counter solvers : Solver instances h_int : interaction hamiltonian previous_mu : dmft chemical potential for which the calculation was just done sum_k : SumK Object instances density_mat : DMFT occupations shell_multiplicity : degeneracy of impurities E_bandcorr : E_kin_dmft - E_kin_dft, either calculated man or from sum_k method if CSC Returns ------- observables: list of dicts """ # init energy values E_corr_en = 0.0 # Read energy from OSZICAR dft_energy = 0.0 if dft_energy is None else dft_energy # now the normal output from each iteration observables['iteration'].append(it) observables['mu'].append(float(previous_mu)) observables['E_bandcorr'].append(E_bandcorr) observables['E_dft'].append(dft_energy) if general_params['calc_energies']: mpi.report('\nCalculating interaction energies') for icrsh in range(sum_k.n_inequiv_shells): if (solver_type_per_imp[icrsh] in ['cthyb', 'hubbardI'] and solver_params[map_imp_solver[icrsh]]["measure_density_matrix"]): mpi.report(f' Imp {icrsh}: from impurity density matrix') # Extract accumulated density matrix density_matrix = solvers[icrsh].density_matrix # Object containing eigensystem of the local Hamiltonian diag_local_ham = solvers[icrsh].h_loc_diagonalization E_int = trace_rho_op(density_matrix, h_int[icrsh], diag_local_ham) elif solver_type_per_imp[icrsh] == 'hartree': mpi.report(f' Imp {icrsh}: from Hartree') E_int = solvers[icrsh].interaction_energy else: mpi.report(f' Imp {icrsh}: from Migdal formula. ' 'WARNING: less stable than measuring density matrix and using trace_rho_op!') # calc energy for given S and G # dmft interaction energy with E_int = 0.5 * Tr[Sigma * G] E_int = 0.5 * np.real((solvers[icrsh].G_freq * solvers[icrsh].Sigma_freq).total_density()) observables['E_int'][icrsh].append(shell_multiplicity[icrsh]*E_int.real) E_corr_en += shell_multiplicity[icrsh] * (E_int.real - sum_k.dc_energ[sum_k.inequiv_to_corr[icrsh]]) observables['E_corr_en'].append(E_corr_en) # calc total energy E_tot = dft_energy + E_bandcorr + E_corr_en observables['E_tot'].append(E_tot) for icrsh in range(sum_k.n_inequiv_shells): if general_params['dc']: observables['E_DC'][icrsh].append(shell_multiplicity[icrsh]*sum_k.dc_energ[sum_k.inequiv_to_corr[icrsh]]) else: observables['E_DC'][icrsh].append(0.0) if solver_type_per_imp[icrsh] != 'ftps': if solvers[icrsh].G_time: G_time = solvers[icrsh].G_time else: G_time = solvers[icrsh].G_time_orig # Collect all occupation and G(beta/2) for spin up and down separately for spin in sum_k.spin_block_names[sum_k.SO]: g_beta_half_per_impurity = 0.0 g_beta_half_per_orbital = [] occupation_per_impurity = 0.0 occupation_per_orbital = [] Z_per_orbital = [] # iterate over all spin channels and add the to up or down for spin_channel in sorted(sum_k.gf_struct_solver[icrsh].keys()): if not spin in spin_channel: continue if solver_type_per_imp[icrsh] == 'ftps': freq_mesh = np.array([w.value for w in solvers[icrsh].G_freq[spin_channel].mesh]) fermi_idx = abs(freq_mesh).argmin() gb2_averaged = solvers[icrsh].G_freq[spin_channel].data[fermi_idx].imag # Z is not defined without Sigma, adding 1 Z_per_orbital.extend( [1.0] * solvers[icrsh].G_freq[spin_channel].target_shape[0] ) else: # G(beta/2) # since G(tau) has always 10001 values we are sampling +-10 values # hard coded around beta/2, for beta=40 this corresponds to approx +-0.05 mesh_mid = len(G_time[spin_channel].data) // 2 samp = 10 gg = G_time[spin_channel].data[mesh_mid-samp:mesh_mid+samp] gb2_averaged = np.mean(np.real(gg), axis=0) # get Z Z_per_orbital.extend( calc_Z(Sigma= solvers[icrsh].Sigma_freq[spin_channel]) ) g_beta_half_per_orbital.extend(np.diag(gb2_averaged)) g_beta_half_per_impurity += np.trace(gb2_averaged) # occupation per orbital and impurity den_mat = np.real(density_mat[icrsh][spin_channel]) occupation_per_orbital.extend(np.diag(den_mat)) occupation_per_impurity += np.trace(den_mat) # adding those values to the observable object observables['orb_gb2'][icrsh][spin].append(np.array(g_beta_half_per_orbital)) observables['imp_gb2'][icrsh][spin].append(g_beta_half_per_impurity) observables['orb_occ'][icrsh][spin].append(np.array(occupation_per_orbital)) observables['imp_occ'][icrsh][spin].append(occupation_per_impurity) observables['orb_Z'][icrsh][spin].append(np.array(Z_per_orbital)) return observables
[docs] def write_obs(observables, sum_k, general_params): """ writes the last entries of the observable arrays to the files Parameters ---------- observables : list of dicts observable arrays/dicts sum_k : SumK Object instances general_params : dict Returns ------- nothing """ n_orb = common.get_n_orbitals(sum_k) for icrsh in range(sum_k.n_inequiv_shells): if general_params['magnetic'] and sum_k.SO == 0: for spin in ('up', 'down'): line = '{:3d} | '.format(observables['iteration'][-1]) line += '{:10.5f} | '.format(observables['mu'][-1]) if n_orb[icrsh][spin] == 1: line += ' '*11 for item in observables['orb_gb2'][icrsh][spin][-1]: line += '{:10.5f} '.format(item) line = line[:-3] + ' | ' if n_orb[icrsh][spin] == 1: line += ' '*11 for item in observables['orb_occ'][icrsh][spin][-1]: line += '{:10.5f} '.format(item) line = line[:-3] + ' | ' line += '{:17.5f}'.format(observables['imp_occ'][icrsh][spin][-1]) if general_params['calc_energies']: line += ' | {:10.5f}'.format(observables['E_tot'][-1]) line += ' | {:10.5f}'.format(observables['E_dft'][-1]) line += ' {:10.5f}'.format(observables['E_bandcorr'][-1]) line += ' {:10.5f}'.format(observables['E_int'][icrsh][-1]) line += ' {:10.5f}'.format(observables['E_DC'][icrsh][-1]) file_name = '{}/observables_imp{}_{}.dat'.format(general_params['jobname'], icrsh, spin) with open(file_name, 'a') as obs_file: obs_file.write(line + '\n') else: line = '{:3d} | '.format(observables['iteration'][-1]) line += '{:10.5f} | '.format(observables['mu'][-1]) # Adds spaces for header to fit in properly if n_orb[icrsh]['up'] == 1: line += ' '*11 # Adds up the spin channels for iorb in range(n_orb[icrsh]['up']): val = np.sum([observables['orb_gb2'][icrsh][spin][-1][iorb] for spin in sum_k.spin_block_names[sum_k.SO]]) line += '{:10.5f} '.format(val) line = line[:-3] + ' | ' # Adds spaces for header to fit in properly if n_orb[icrsh]['up'] == 1: line += ' '*11 # Adds up the spin channels for iorb in range(n_orb[icrsh]['up']): val = np.sum([observables['orb_occ'][icrsh][spin][-1][iorb] for spin in sum_k.spin_block_names[sum_k.SO]]) line += '{:10.5f} '.format(val) line = line[:-3] + ' | ' # Adds up the spin channels val = np.sum([observables['imp_occ'][icrsh][spin][-1] for spin in sum_k.spin_block_names[sum_k.SO]]) line += '{:17.5f}'.format(val) if general_params['calc_energies']: line += ' | {:10.5f}'.format(observables['E_tot'][-1]) line += ' | {:10.5f}'.format(observables['E_dft'][-1]) line += ' {:10.5f}'.format(observables['E_bandcorr'][-1]) line += ' {:10.5f}'.format(observables['E_int'][icrsh][-1]) line += ' {:10.5f}'.format(observables['E_DC'][icrsh][-1]) file_name = '{}/observables_imp{}.dat'.format(general_params['jobname'], icrsh) with open(file_name, 'a') as obs_file: obs_file.write(line + '\n')
[docs] def calc_dft_kin_en(general_params, sum_k, dft_mu): """ Calculates the kinetic energy from DFT for target states Parameters ---------- general_params : dict general parameters as a dict sum_k : SumK Object instances dft_mu: float DFT fermi energy Returns ------- E_kin_dft: float kinetic energy from DFT """ H_ks = sum_k.hopping num_kpts = sum_k.n_k E_kin = 0.0 ikarray = np.array(list(range(sum_k.n_k))) for ik in mpi.slice_array(ikarray): nb = int(sum_k.n_orbitals[ik]) # calculate lattice greens function need here to set sigma other n_iw is assumend to be 1025! # TODO: implement here version for FTPS! G_freq_lat = sum_k.lattice_gf(ik, with_Sigma=True, mu=dft_mu).copy() # # calculate G(beta) via the function density, which is the same as fourier trafo G(w) and taking G(b) G_freq_lat_beta = G_freq_lat.density() for spin in sum_k.spin_block_names[sum_k.SO]: E_kin += np.trace(np.dot(H_ks[ik, 0, :nb, :nb], G_freq_lat_beta[spin][:, :])) E_kin = np.real(E_kin) # collect data and put into E_kin_dft E_kin_dft = mpi.all_reduce(E_kin) mpi.barrier() # E_kin should be divided by the number of k-points E_kin_dft = E_kin_dft/num_kpts mpi.report(f'Kinetic energy contribution dft part: {E_kin_dft:.8f}') return E_kin_dft
[docs] def calc_bandcorr_man(general_params, sum_k, E_kin_dft): """ Calculates the correlated kinetic energy from DMFT for target states and then determines the band correction energy Parameters ---------- general_params : dict general parameters as a dict sum_k : SumK Object instances E_kin_dft: float kinetic energy from DFT Returns ------- E_bandcorr: float band energy correction E_kin_dmft - E_kin_dft """ E_kin_dmft = 0.0j E_kin = 0.0j H_ks = sum_k.hopping num_kpts = sum_k.n_k # kinetic energy from dmft lattice Greens functions ikarray = np.array(list(range(sum_k.n_k))) for ik in mpi.slice_array(ikarray): nb = int(sum_k.n_orbitals[ik]) # calculate lattice greens function G_freq_lat = sum_k.lattice_gf(ik, with_Sigma=True, with_dc=True).copy() # calculate G(beta) via the function density, which is the same as fourier trafo G(w) and taking G(b) G_freq_lat_beta = G_freq_lat.density() for spin in sum_k.spin_block_names[sum_k.SO]: E_kin += np.trace(np.dot(H_ks[ik, 0, :nb, :nb], G_freq_lat_beta[spin][:, :])) E_kin = np.real(E_kin) # collect data and put into E_kin_dmft E_kin_dmft = mpi.all_reduce(E_kin) mpi.barrier() # E_kin should be divided by the number of k-points E_kin_dmft = E_kin_dmft/num_kpts if mpi.is_master_node(): print('Kinetic energy contribution dmft part: '+str(E_kin_dmft)) E_bandcorr = E_kin_dmft - E_kin_dft return E_bandcorr
[docs] def calc_Z(Sigma): """ calculates the inverse mass enhancement from the impurity self-energy by a simple linear fit estimate: [ 1 - ((Im S_iw[n_iw0+1]-S_iw[n_iw0])/(iw[n_iw0+1]-iw[n_iw0])) ]^-1 Parameters ---------- Sigma: Gf on MeshImFreq self-energy on Matsubara mesh Returns ------- orb_Z: 1d numpy array list of Z values per orbital in Sigma """ orb_Z = [] iw = [np.imag(n) for n in Sigma.mesh] # find smallest iw_n n_iw0 = int(0.5*len(iw)) for orb in range(0,Sigma.target_shape[0]): Im_S_iw = Sigma[orb,orb].data.imag # simple extraction from linear fit to first two Matsubara freq of Sigma # assuming Fermi liquid like self energy Z = 1/(1 - (Im_S_iw[n_iw0+1]-Im_S_iw[n_iw0]) / (iw[n_iw0+1]-iw[n_iw0]) ) orb_Z.append(abs(Z)) return np.array(orb_Z)