The most basic way to start CONVERGE in parallel is
mpirun -n <number of processes> converge-mpich
For example, to start a job on four processing cores you would type
mpirun -n 4 converge-mpich
In practice, however, a few things should be added to the mpirun command line to make it more practical. To write the output to a file and start the job in the background, use
mpirun -n 4 converge-mpich < /dev/null > logfile.out &
The redirect of the /dev/null is recommended by MPICH to avoid some warnings that would otherwise be sent to stdout.