ABINIT Discussion Forums

Dear all,

I am using the last version of abinit (7.6.1) and the documentation is not available online, so I am still considering documentation of version 7.4.
I want to use, the variable paral_kgb with negative values to evaluate optimal number of processors, which is very useful, however negative values are now rejected with the following error message:

--- !ERROR
message: |
Input paral_kgb must be 0 or 1, but was -2000
for dataset0. This is not allowed.
Action: check the input file.
src_file: Subroutine Unknown
src_line: 0
...

It seems that something changed but is unexplained. Could someone provide me more informations please and how to get optimal number of processors.
Thanks,

Emile

Negative values of paral_kgb are not supported anymore.
Now there's a new variable (max_ncpus) that specifies the maximum number of MPI nodes that
will be analyzed by the algorithm that computes an estimate for the parallel efficiency.

Example

# OLD VERSION
paral_kgb -108

# NEW VERSION
paral_kgb 1 # Will use the paral_kgb algorithm for the GS run
max_ncpus 108 # Will analyze all the possible configurations of parameters used for paral_kgb=1
# (i.e. npband, npfft ...) and num_MPI_nodes <= 108.

The big advantage of the new approach is that now it's possible to use
the automatic parallelization also in the other parts of the code (GW, BSE, band-by-band conjugate gradient ...)

Thanks a lot, that is exactly what I wanted to know.