[QE-users] Absorption spectra of a bulk material

[Vipul Shivaji Ghemud]

Dear all,

For a system (experimentally which is semi-conductor) with GGA calculation
I am getting band crossing i.e., no band gap. But, when I add HSE flags I
get around 2 eV gap (which is desired). I have optimized the parameters
and K-mesh (6 6 3 0 0 0). I want to calculate absorption coefficient of
this system. I first run the scf, followed by turbo_davidson file and
finally turbo_spectrum. But, while doing the turbo_davidson processing, I
am getting following output and the run stops:



"     Program turboTDDFT v.6.1 (svn rev. 13369) starts on  8May2019 at 16:
2:30

     This program is part of the open-source Quantum ESPRESSO suite
     for quantum simulation of materials; please cite
         "P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009);
          URL http://www.quantum-espresso.org",
     in publications or presentations arising from this work. More details at
     http://www.quantum-espresso.org/quote

     Parallel version (MPI), running on    28 processors
     R & G space division:  proc/nbgrp/npool/nimage =      28

     Reading data from directory:
     ./out/cfts.save
     Message from routine read_xml_file:
     file ./out/cfts.save not guaranteed to be safe for post-processing

   Info: using nr1, nr2, nr3 values from input

   Info: using nr1, nr2, nr3 values from input
td.out (END) "


I am getting the same message for GGA calculation also. I have given
K_POINTS (GAMMA). Currently I am using .pbe-mt_fhi.UPF pseudopotential,
what type of pseudopotential is to be used ? Please suggest where am I
going wrong ?



Thanks in advance



-- 
Vipul S. Ghemud
Ph.D. student.
Dept of Physics,
SPPU, Ganeshkhind,
Pune- 411007.