Greetings, and apologies: In mpich, I could assign MPI_WORLD_COMM (i.e., mpich did not accept MPI_WORLD_COMM in a common block either) to an integer and that was what I put into the common block,. Openmpi does not accept that new integer as a communicator.
Mihaly Mezei Department of Structural and Chemical Biology, Mount Sinai School of Medicine Voice: (212) 659-5475 Fax: (212) 849-2456 WWW (MSSM home): http://www.mountsinai.org/Find%20A%20Faculty/profile.do?id=0000072500001497192632 WWW (Lab home - software, publications): http://inka.mssm.edu/~mezei WWW (Department): http://atlas.physbio.mssm.edu