ABINIT Discussion Forums

Hello-

The code fails to write out the KSS file when using the paral_kg =1. The error message is,

m_io_kss.F90:1435:ERROR
Unsupported value for accesswff: 1

This the build information:

=== Build Information ===
Version : 6.0.1
Build target : x86_64_linux_intel11.1
Build date : 20100220

=== Compiler Suite ===
C compiler : gnu
CFLAGS : -g -O2 -march=opteron
C++ compiler : gnu4.3
CXXFLAGS : -g -O2 -march=opteron
Fortran compiler : intel11.1
FCFLAGS : -g -extend-source -vec-report0
FC_LDFLAGS : -i-static -static-libcxa

=== Optimizations ===
Debug level : yes
Optimization level : standard
Architecture : amd_opteron

=== MPI ===
Parallel build : yes
Parallel I/O : yes

=== Linear algebra ===
Library type : abinit
Use ScaLAPACK : yes

=== Plug-ins ===
BigDFT : yes
ETSF I/O : yes
LibXC : no
FoX : no
NetCDF : yes
Wannier90 : yes

=== Experimental features ===
Bindings : no
Error handlers : no
Exports : no
GW double-precision : no
Macroave build : yes

==========================
I am testing it using a simile N2 in a box case. Input file is,

paral_kgb 1

# Definition of parameters for the calculation of the KSS file
nbandkss -1 # Number of bands in KSS file (-1 means the maximum possible)
nband 8 # Number of (occ and empty) bands to be computed
#istwfk 10*1

#
acell 15.2 15.3 18.3

# Definition of the atom types
ntypat 1
znucl 7

natom 2 # There are two atoms
typat 1 1 # They both are of type 1, that is, Silicon.
xangst # Reduced coordinate of atoms
0.0 0.0 0.0
0.0 0.0 1.4

ngkpt 1 1 1
nkpt 1
kpt 0 0 0
nshiftk 1
shiftk 0 0 0

istwfk 10*1

symmorphi 0

ecut 25.0

nstep 2
toldfe 1.0d-6
diemac 12.0
#kssform 1
#accesswff 3

========================================

Tried several choices for accesswff but none worked.

Thank you in advance for any suggestions.

Wissam Al-Saidi
Univ of Pittsburgh

Dear Wissam,

At present one cannot generate the KSS file when the calculation
is performed with the band-fft parallelization.
For the time being one has to resort to the following procedure:

1) GS + NSCF calculation with paral_kb = 1 and MPI-IO
Note that MPI-IO is mandatory in order to have a complete
WFK file at the end of the run. Besides the NSCF run should
include all the states you are going to use in the GW part (both
empty and occupied).

2) Run the KSS generation in a completely separate input file
with paral_kgb=0 and kssform=3, and ask the code to read the previously
generated WFK file via getwfk or irdwfk.
Remember that one should use the same value for nband as that used in the NSCF run of point 1
otherwise some of the bands stored in the WFK file won't be read.
nstep can be safely set to 0 for this run since the input WFK file is already well converged.
With this trick the code will skip the NSCF cycle and
it will immediately convert the WFK file into the KSS file

BTW: Avoid the use of toldfe to stop the GS calculation when high energy empty states are included.
See the discussion at

viewtopic.php?f=11&t=68

Best regards
Matteo Giantomassi

Dear Matteo,

Thank you very much for your help.

Best, Wissam