Dear gmxeers, I've installed the parallel version of the Gromacs 3.2.1 on the IBM p655 machine. However there is only 'mpiexec' file available related to mpi in the machine. I'm not confident with my question, but is it possible to perform 'mdrun_mpi' with 'mpiexec' instead of 'mpirun'? if yes, then how? Thanks in advance. All the best, Sekwan