Dr. Abraham and other users Thanks for the detailed explanation.
I compiled using the Intel MPI C and C++ compilers as evident by the cmake flags, in my first mail on this topic. I am a novice in this area, and , after you pointed out about the mix in MPI versions I looked up the net and found that "mpiexec" is associated with MPICH and I am thinking that the PBS scheduler of my university cluster uses this MPI version for distributing job across the compute nodes. So , is there any way around this problem? I mean to ask if I am recompiling GROMACS then what specific things should I be careful of and what flags should I be using ? I looked up the installation guide but could not figure out a solution. I am at present forced to use only 1 node and 16 processes. ( np = 16 in mpirun ). Regarding compilation with OpenMPI, instead of Intel MPI , is it compatible with the MPICH ? Also as MPICH is already there in the cluster , then why does it cause problem with the present installation of GROMACS? I did not find an installation guide for it in the GROMACS website but I found this link : http://flakrat.blogspot.com/2013/04/how-to-compile-gromacs-461-with-openmpi.html I think it is well explained and should work with GROMACS 4.6.7. Any suggestions ? Thanks & Regards Agnivo Gosai Grad Student, Iowa State University. -- Gromacs Users mailing list * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before posting! * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists * For (un)subscribe requests visit https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or send a mail to gmx-users-requ...@gromacs.org.