Inequivalent Impurities Solver Routines

The module E2I_MAIN contains the procedures that initializes, launch and finalize multiple EDIpack2 solvers for independent inequivalent quantum impurity problems.

The functionalities of the main EDIpack2 functions are here naturally extended to the case of multiple impurities: ed_init setups and allocates all the internal variables and memory used in the code, which remain available to the user until ed_finalize is called.

The ed_solve functions aims to diagonalize the impurity problems, evaluate the dynamical response functions and local observables using different parallelization schemes according to the value of the input variable mpi_lanc: serial on the inequivalent impurities and parallel in the diagonalization, parallel on the inequivalent impurities and serial in the diagonalization.

Description

Contains routine that initialize, run and finalize the Impurity model solver

Quick access

Routines:

ed_finalize_solver(), ed_init_solver(), ed_solve()

Used modules

  • edipack2: EDIpack2.0 library frontend

  • e2i_vars_global: Global variables, inequivalent sites version

  • e2i_aux_funx: Assortment of auxiliary procedures, inequivalent sites version

  • e2i_bath: Bath module: real-space DMFT extension

External modules

Subroutines and functions

interface  e2i_main/ed_init_solver(bath)

Initialize the Exact Diagonalization solver of EDIpack2.0. This procedure reserves and allocates all the memory required by the solver, performs all the consistency check and initializes the bath instance guessing or reading from a file. It requires as an input a double precision array of rank-2 [ nb , nlat ] for the Real space DMFT case. nlat is the number of inequivalent impurity sites, while nb depends on the bath size and geometry and can be obtained from get_bath_dimension() .

Parameters:

bath (•, •) [real, inout] – user bath input array

interface  e2i_main/ed_solve(bath[, mpi_lanc, uloc_ii, ust_ii, jh_ii, jp_ii, jx_ii, flag_gf])

Launch the Exact Diagonalizaton solver for the single-site and multiple-site (R-DMFT) quantum impurity problem. It requires as an input a double precision array of rank-2 [ nb , nlat ] for the Real space DMFT case. nlat is the number of inequivalent impurity sites, while nb depends on the bath size and geometry and can be obtained from get_bath_dimension() .

The solution is achieved in this sequence:

  1. setup the MPI environment, if any

  2. Set the internal bath instance dmft_bath copying from the user provided input bath

  3. Get the low energy spectrum: call diagonalize_impurity()

  4. Get the impurity Green's functions: call buildgf_impurity() (if sflag = .true. )

  5. Get the impurity susceptibilities, if any: call buildchi_impurity() (if sflag = .true. )

  6. Get the impurity observables: call observables_impurity()

  7. Get the impurity local energy: call local_energy_impurity()

  8. Get the impurity reduced density matric: call rdm_impurity()

  9. Delete MPI environment and deallocate used structures state_list and dmft_bath

Parameters:

bath (•, •) [real, in,required] – user bath input array

Options:

  • mpi_lanc [logical] – parallelization strategy flag: if .false. each core serially solves an inequivalent site, if .true. all cores parallely solve each site in sequence. Default .false. .

  • uloc_ii (size(bath, 1), norb) [real] – site-dependent values for uloc , overriding the ones in the input file. It has dimension [ nlat , norb ].

  • ust_ii (size(bath, 1)) [real] – site-dependent values for ust , overriding the ones in the input file. It has dimension [ nlat].

  • jh_ii (size(bath, 1)) [real] – site-dependent values for jh , overriding the ones in the input file. It has dimension [ nlat].

  • jp_ii (size(bath, 1)) [real] – site-dependent values for jp , overriding the ones in the input file. It has dimension [ nlat].

  • jx_ii (size(bath, 1)) [real] – site-dependent values for jx , overriding the ones in the input file. It has dimension [ nlat].

  • flag_gf [logical] – flag to calculate ( .true. ) or not ( .false. ) Green's functions and susceptibilities. Default .true. .

interface  e2i_main/ed_finalize_solver(nineq)

Finalize the Exact Diagonalization solver, clean up all the allocated memory.

Parameters:

nineq [integer] – number of inequivalent impurity sites for real-space DMFT