Mvapich version 0.9.9  (based upon mpich version 1) is available for the gnu compilers and uses the OpenFabrics stack to access the infiniband network. To setup an environment for mpich version 1, execute one of following based on your shell:

for c-shell users

source /usr/local/profile.d/mpichv1-gnu.csh

for bourne shell users

source /usr/local/profile.d/mpichv1-gnu.sh

Once setup, users should find in their path mpicc, mpiCC, mpif90 and mpif77.  MOAB job submissions should include the line above so that the environment is setup for mpich on the compute nodes.  Then mpich jobs can be run as usual with the machinefile argument replaced by $PBS_NODEFILE.