atom.tmat.in

Introduction

The purpose of the atom.tmat.in file is to supply the transformation matrix $\mathcal{T}_{\alpha\beta}$, which transforms an operator from its original basis to the natural basis. Only when ibasis = 2, the atom.tmat.in file is used. See ibasis for more details.

Format

The format of the atom.tmat.in file is as follows:

column 1: orbital index $\alpha$, integer

column 2: orbital index $\beta$, integer

column 3: elements of the transformation matrix $\mathcal{T}_{\alpha\beta}$, double precision

Note

In the atom.tmat.in file, we adopt the following orbital sequence: $1\uparrow$, $2\uparrow$, $3\uparrow$, $\cdots$, $1\downarrow$, $2\downarrow$, $3\downarrow$, $\cdots$ In other words, the spin up part is always before the spin down part.

Code

The corresponding Fortran code block for the reading of the atom.tmat.in file is as follows:

! open file atom.tmat.in
open(mytmp, file='atom.tmat.in', form='formatted', status='unknown')

! read the data file
do i=1,norbs
    do j=1,norbs
        read(mytmp,*) i1, i2, raux
        ! tmat is actually real
        tmat(i,j) = dcmplx(raux, zero)
    enddo ! over j={1,norbs} loop
enddo ! over i={1,norbs} loop

! close data file
close(mytmp)

In principle, the transformation matrix is complex. Here we think that its imaginary part is zero and only take the real part into consideration.