Trans file

This file determines the coefficients of the transfer integrals \(t_{ij\sigma_1\sigma_2}\) in the Hamiltonian

(2.3)\[\begin{aligned} \mathcal{H} = -\sum_{ij\sigma_1\sigma_2} t_{ij\sigma_1\sigma_2}c_{i\sigma_1}^{\dagger}c_{j\sigma_2}^{\phantom{\dagger}}. \end{aligned}\]

An example of the file format is presented below.

========================
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: [ntransfer] [count]

  • Lines 3-5: Header

  • Lines 6-: [i] [s1] [j] [s2]  [v.real] [v.imag]

Parameters

  • [ntransfer]

    Type : String (blank is not allowed)

    Description : An arbitrary keyword for the total number of transfer integrals.

  • [count]

    Type : Integer (blank is not allowed)

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

  • [i], [j]

    Type : Integer (blank is not allowed)

    Description : An integer giving a site index (\(0 \le i, j < {\rm Nsite}\)).

  • [s1], [s2]

    Type : Integer (blank is not allowed)

    Description : An integer giving a spin index: either 0 (up-spin) or 1 (down-spin).

  • [v.real], [v.imag]

    Type : Float (blank is not allowed)

    Description : Values for the real and imaginary parts of \(t_{ij\sigma_1\sigma_2}\), respectively.

Usage rules

  • Headers cannot be omitted.

  • Since the Hamiltonian should be hermite, the coefficients must satisfy the relation \(t_{ij\sigma_1\sigma_2}=t_{ji\sigma_2\sigma_1}^{\dagger}\). Otherwise, the program is terminated or a warning is reported, depending on the strict_hermite parameter.

  • The program is terminated with error if there are duplicated entries.

  • The program is terminated with error when the number of entries is different from [count].

  • The program is terminated with error if [i], [j], [s1], or [s2] are outside the range of the defined values.