Input files

bse.in

bse.in is a file that contains parameters for chiq_main.py and chiq_post.py in the TOML format. Below is a template of the input file.

[chiq_common]
input = "dmft_bse.h5"
output = "dmft_bse.out.h5"
type = ["chi0", "bse", "rpa", "rrpa"]  # "chi0", "bse", "scl", "rpa", "rrpa"
omega_q = "q_path.dat"

[chiq_main]
work_dir = "work/chiq"
# num_wf = 20  # If not specified, the value is determined from X_loc

[chiq_post]
output_dir = ""
mode = ["eigen"]  # "matrix_element", "eigen", "linear_combination"

# for mode="eigen"
#vector = true  # output eigenvectors
#order = "file"  # "descend" (default), "overlap", "file"
#order_file = "/path/to/eigenvec.in"  # for order="file"

# for mode="linear_combination"
# coefs_file = "/path/to/coefs.in"

The [chiq_common] section contains general settings that apply to both programs chiq_main.py and chiq_post.py. In contrast, the [chiq_main] and [chiq_post] sections provide configurations that are specific to each program.

[chiq_common] section

Name

Type

Default

Description

input

string

"dmft_bse.h5"

Filename that contain input data in HDF5 format.

output

string

"dmft_bse.out.h5"

Filename to store output data in HDF5 format. This can be the same as parameter input.

type

list

["bse"]

List of calculation schemes. Specify one or more from "chi0", "bse", "scl", "rpa", "rrpa".

omega_q

string

Not specified

Filename storing the omega-q list to be computed. If not specified, omega-q list are generated from X0(q) in the input HDF5 file.

[chiq_main] section

Name

Type

Default

Description

work_dir

string

""

Working directory where intermediate files are stored. The empty string (default value) means the current directory.

num_wf

int

Not specified

Number of fermionic Matsubara frequencies. If not specified, num_wf is determined from X_loc in the input HDF5 file. num_wf can be smaller than the actual number of Matsubara frequencies in the input file.

[chiq_post] section

Name

Type

Default

Description

output_dir

string

""

Output directory for the results. The empty string (default value) means the current directory.

mode

list

["eigen"]

Types of the output. Specify one or more from "matrix_element", "eigen", "linear_combination".

vector

bool

false

[mode=’eigen’] If set to ture, eigenvectors are output.

order

string

"descend"

[When mode="eigen"] Sorting order of eigenvalues: "descend", "overlap", "file". For "descend", eigenvalues are sorted in descending order for eqch q. For "overlap", eigenvalues are sorted based on overlap with the eigenvectors for the previous q. For "file", the order is specified by an external file.

order_file

string

"eigenvec.in"

[When mode="eigen" and order="file"] Filename that contains sequence of vectors that specify the order of the eigenvalues.

coefs_file

string

"coefs.in"

[When mode="linear_combination"] Filename that contains coefficients for the linear combination of eigenvectors.

qpath.in

qpath.in is an input file for gen_qpath.py for generating a q-path. The file specifies the symmetry points in the Brillouin zone and the path connecting them. Below is an example of the input file.

# qx qy qz name  (in unit of reciprocal lattice vectors)
1/2 0 0  X
0 0 0  Gamma
1/2 1/2 0  M
1/2 0 0  X
1/4 1/4 0  M'

Lines starting with # are comments. Each line consists of four values: the components of the wave vector and the name of the point. The wave vector is specified in units of the reciprocal lattice vectors, and users can use fractions like 1/2 and 1/4. The name of the point will be used in the plotting.

q_path.dat

q_path.dat specifies the \((\boldsymbol{q}, i\Omega_m)\) points for the calculation of the two-particle susceptibilities. This has four columns. The first column is the index \(m\) of the Matsubara frequency \(\Omega_m\). The second column is the three integers X.Y.Z separated by a dot without any spaces, which specify the momentum \(\boldsymbol{q} = 2\pi/a \times [X, Y, Z]\) where \(a\) is the lattice constant. The third column is the distance from the starting point along the path. The optional fourth column is the name of the point, which is used for labeling the plot. An example of q_path.dat is as follows

0 16.00.00   0.00000 X
0 15.00.00   0.03125
0 14.00.00   0.06250
0 13.00.00   0.09375
0 12.00.00   0.12500
0 11.00.00   0.15625
   ... continued ...

eigenvec.in

eigenvec.in is an input file for chiq_post.py to specify the order of the eigenvectors when mode = "eigen" and order = "file". This files specifies the transform matrix \(U\) in the equation (13) in the Algorithm section. The format is the same as that of the eigenvectors files generated by chiq_main.py, so see the reference of the output files for details.

coeff.in

coeff.in is an input file for chiq_post.py to specify the coefficients for the linear combination of the density operators when mode = "linear_combination". This files specifies the transform matrix \(C\) in the equation (14) in the Algorithm section. The format is the same as that of the eigenvectors files generated by chiq_main.py, so see the reference of the output files for details.