if (intercomm != MPI_COMM_NULL) {
MPI_Comm_size (intercomm, &dnprocs);
MPI_Comm_rank (intercomm, &drank);
MPI_Comm_remote_size (intercomm, &rnprocs);
if (intercomm != MPI_COMM_NULL) {
MPI_Comm_size (intercomm, &dnprocs);
MPI_Comm_rank (intercomm, &drank);
MPI_Comm_remote_size (intercomm, &rnprocs);