[Wien] some comments on parallel execution of wien2k

[Andres Saul]

Dear wien users:
   I can also confirm that there is a problem with lapw2_mpi and
openmpi for some specific combinations of
the number of atoms and number of processors. The same calculations
with mpich or hpmpi work fine.
   Looking at the source files I concluded that the problem was
related to using a negative second argument
in MPI_COMM_SPLIT in line 327 of l2main.F (wien2k v9.1).

   I have found that a simple dirty solution consisting in changing
line 319 from
         iatm_proc_pack=-(nat+npe+jatom_pe)
to
         iatm_proc_pack=10000-(nat+npe+jatom_pe)
   was enough to solve the problem. I my opinion the occurrence of the
error for a given number of atoms or specific number of processors is
related to the "if then else" structure around this line.

Regards
Andres Saul