[Pw_forum] Solved! Re: Problems running PWscf in parallel

[stewart at cnf.cornell.edu]

Hi all, 

  Through some helpful comments from pwscf users, I have been able to get 
the parallel version of the espresso package to compile with lam-mpi and 
ifort v8.1.  I was running into a problem where MPI crashed on multiple 
processor runs with the following statement 

MPI_Allreduce: invalid operation: Invalid argument (rank 0, MPI_COMM_WORLD)
Rank (0, MPI_COMM_WORLD): Call stack within LAM:
Rank (0, MPI_COMM_WORLD):  - MPI_Allreduce()
Rank (0, MPI_COMM_WORLD):  - main() 

Marco Fornari suggested changing the following three lines of f_def.h
in the include directory from 

#if defined(__LAM) && ( defined (__LINUX) || defined (__LINUX64) )
#define MPI_REAL8 MPI_DOUBLE_PRECISION
#endif 

to 

#if defined(__LAM) || ( defined (__LINUX) || defined (__LINUX64) )
#define MPI_REAL8 MPI_DOUBLE_PRECISION
#endif 

When I recompiled the code with this fix, I had no problems running pw.x in 
parallel on multiple processors.  This change might be a good thing to 
implement in the next version of the espresso package. 

Thanks again, 

Derek 

################################
Derek Stewart, Ph. D.
Scientific Computation Associate
250 Duffield Hall
Cornell Nanoscale Facility (CNF)
Ithaca, NY 14853
stewart (at) cnf.cornell.edu