If you have access to a 256 node cluster and can run calculations on all nodes, assuming that the dauvergne_protocol.py automated model-free analysis sample script will be used (after modification for the system under study), relax can be executed by typing:
$ mpirun -np 257 /usr/local/bin/relax -multi=`mpi4py' -tee log dauvergne_protocol.py
Note that the argument -np value is one more than the number of slaves you would like to run. You should then see the following text in the initial relax printout:
Processor fabric: MPI 2.1 running via mpi4py with 256 slave processors & 1 master. Using Open MPI 1.4.3.