lammps fortran version, FFT problem


There is a communication problem between C and fortran,
when they are used with openmpi. There is no problem, if you use mpich or mpich2.

When using openmpi, the code crashes in line 602 in "fft_3d.c" where the MPI_Comm_rank(comm,&me) is executed. This happens because the <<comm>> variable in "fft_3d.c" has different default value from the fortran <<MPI_COMM_WORLD>>.

If you insist on using openmpi, then you should replace the <<comm>> variable in fft_3d.c with MPI_COMM_WORLD inside all mpi commands; then the code should run without any problem.

More details about this problem, please see

Takis Kolokathis

School of Chemical Engineering

National Technical University of Athens