4.2.5. Trans file

This file determines the values of the transfer integrals \(t_{ij\sigma_1\sigma_2}\),

(4.7)\[{\mathcal H} +=-\sum_{ij\sigma_1\sigma_2} t_{ij\sigma_1\sigma_2}c_{i\sigma_1}^{\dagger}c_{j\sigma_2}.\]

An example of the file format is as follows.

========================
NTransfer      24
========================
========i_j_s_tijs======
========================
    0     0     2     0   1.000000  0.000000
    2     0     0     0   1.000000  0.000000
    0     1     2     1   1.000000  0.000000
    2     1     0     1   1.000000  0.000000
    2     0     4     0   1.000000  0.000000
    4     0     2     0   1.000000  0.000000
    2     1     4     1   1.000000  0.000000
    4     1     2     1   1.000000  0.000000
    4     0     6     0   1.000000  0.000000
    6     0     4     0   1.000000  0.000000
    4     1     6     1   1.000000  0.000000
    6     1     4     1   1.000000  0.000000
    6     0     8     0   1.000000  0.000000
    8     0     6     0   1.000000  0.000000
...

File format

  • Line 1: Header

  • Line 2: [string01] [int01]

  • Lines 3-5: Header

  • Lines 6-: [int02]  [int03]  [int04]  [int05]  [double01]  [double02].

Parameters

  • [string01]

    Type : String (a blank parameter is not allowed)

    Description : A keyword for the total number of transfer integrals. You can freely give a name to the keyword.

  • [int01]

    Type : Int (a blank parameter is not allowed)

    Description : An integer giving the total number of transfer integrals.

  • [int02], [int04]

    Type : Int (a blank parameter is not allowed)

    Description : An integer giving a site index (\(0<=\) [int02], [int04] \(<\) Nsite ).

  • [int03], [int05]

    Type : Int (a blank parameter is not allowed)

    Description : An integer giving a spin index:
    0: Up-spin
    1: Down-spin.

  • [double01]

    Type : Double (a blank parameter is not allowed)

    Description : A value for a real part of \(t_{ij\sigma_1\sigma_2}\).

  • [double02]

    Type : Double (a blank parameter is not allowed)

    Description : A value for an imaginary part of \(t_{ij\sigma_1\sigma_2}\).

Use rules

  • Headers cannot be omitted.

  • Since the Hamiltonian must be Hermitian, the relation \(t_{ij\sigma_1\sigma_2}=t_{ji\sigma_2\sigma_1}^{\dagger}\) must be satisfied. A program is terminated when this relation is broken.

  • A program is terminated when the components of the on-site interactions are double counted.

  • A program is terminated when [int01] is different from the total number of transfer integrals defined in this file.

  • A program is terminated when [int02]-[int05] are outside the range of the defined values.