solver.kernel.dat

Introduction

The solver.kernel.dat is designed to store the screening function $K(\tau)$ and it derivates $K'(\tau)$ in imaginary-time space. It will be output by the quantum impurity solvers when they are shut down.

Note

The screening function $K(\tau)$ and its derivates $K'(\tau)$ are the input to the quantum impurity solvers (see solver.ktau.in for more details). In other words, they won't be changed by the quantum impurity solvers.
Only the NARCISSUS component can generate the solver.kernel.dat file.

Format

The solver.kernel.dat file only contains one block. The format of the block is as follows:

column 1: index of imaginary-time point, integer

column 2: imaginary-time point, $\tau$, double precision

column 3: screening function, $K(\tau)$, double precision

column 4: the first derivate of screening function, $K'(\tau)$, double precision

column 5: the second derivate of screening function, $K''(\tau)$, double precision

column 6: the third derivate of screening function, $K'''(\tau)$, double precision

Note

In the NARCISSUS component, the $K(\tau)$ and $K'(\tau)$ are assumed to be orbital-independent.

Code

The corresponding Fortran code block for the writing of solver.kernel.dat file is as follows:

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

! write it
     do i=1,ntime
         write(mytmp,'(i6,5f12.6)') i, tmesh(i), ktau(i), ptau(i), ksed(i), psed(i)
     enddo ! over i={1,ntime} 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.kernel.dat file. See script/u_reader.py for more details.