calc_Iq

calc_Iq.py [-h] [-f FILE] [--remove REMOVE | --retain RETAIN] [-w W]
           [--verbose]

Description

calc_Iq.py is a script for calculating the momentum-dependent interactions from the susceptibility, assuming a localized model. This script should be run after the BSE calculation by chiq_main.py. For the explicit equation, see Intersite interactions.

Options

-h, –help

Show this help message and exit.

-f FILE, –file FILE

Specify the HDF5 filename. Default is "dmft_bse.out.h5". The file should contain chi_loc and chi_q data. The results are stored as I_q (overwritten if data exist).

–remove REMOVE

Specify the number of eigenmodes to remove. Default is 1, typically used to exclude the charge susceptibility.

–retain RETAIN

Specify the number of eigenmodes to retain. Cannot be used simultaneously with --remove.

-w W

Specify the bosonic Matsubara frequency. Default is 0 (static susceptibility).

–verbose

Enable verbose output for detailed execution logs.

Note

Options --remove and --retain are mutually exclusive.

Example

Example for using calc_Iq.py in the single-orbital Hubbard model:

$ calc_Iq.py
Namespace(file='dmft_bse.out.h5', remove=1, retain=None, w=0, verbose=False)

Load data from 'dmft_bse.out.h5'
inner_name: [b'0-0']
block_name: [b'0-up-0-up', b'0-up-0-down', b'0-down-0-up', b'0-down-0-down']

Load 'chi_loc'
'chi_loc' found

Diagonalize chi_loc
Number of eigenmodes retained = 3
0: 0.9996646498695337
1: 0.9996646498695336
2: 0.9996646498695334
------------------------- Remove eigenmodes below
3: 0.0003353501304669271

55 data of 'chi_q' found
Compute 'I_q' (existing data are overwritten)

Start q-loop
End q-loop

The description “————————- Remove eigenmodes below” indicates that the charge mode with the smallest eigenvalue of chi_loc is removed by default (--remove 1). This treatment ensures a stable inversion of the chi_loc matrix.

The results are saved as I_q in the HDF5 file.

$ h5ls dmft_bse.out.h5/bse/output
I_q                      Group
chi0_loc                 Group
chi0_q                   Group
chi_loc                  Group
chi_q                    Group

Note

The file dmft_bse.out.h5 originally contains I_q computed in chiq_main.py. It corresponds to a result with no remove option --remove 0. However, removing the charge mode is crucial especially in the strong-coupling regime. We recommend using calc_Iq.py and removing small eigenvalues manually.