solver.grn.dat

Introduction

This file is used to store the Matsubara Green's function $G(i\omega_n)$. It will be output by the quantum impurity solvers when they are shut down.

Format

The solver.grn.dat file contains norbs block. Each block is appended by two blank lines. The format of each block is as follows:

column 1: orbital index $i$, integer

column 2: Matsubara frequency point, $\omega_n$, double precision

column 3: Matsubara Green's function, $\Re G(i\omega_n)$, double precision

column 4: Matsubara Green's function, $\Im G(i\omega_n)$, double precision

column 5: error bar, $\Re [\delta G(i\omega_n)]$, double precision

column 6: error bar, $\Im [\delta G(i\omega_n)]$, double precision

Note

In the solver.grn.dat 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 writing of solver.grn.dat file is as follows:

! open data file: solver.grn.dat
     open(mytmp, file='solver.grn.dat', form='formatted', status='unknown')

! write it
     do i=1,norbs
         do j=1,mfreq
             write(mytmp,'(i6,5f16.8)') i, rmesh(j), &
              real(grnf(j,i,i)), aimag(grnf(j,i,i)), &
              real(gerr(j,i,i)), aimag(gerr(j,i,i))
         enddo ! over j={1,mfreq} loop
         write(mytmp,*) ! write empty lines
         write(mytmp,*)
     enddo ! over i={1,norbs} loop

! close data file
     close(mytmp)

In the HIBISCUS component, we provide a Python module to read the output files of quantum impurity solvers. You can use it to read the solver.grn.dat file. See script/u_reader.py for more details.