def mpicommand(self, *args, **kwargs):
if self.mpiexec is None:<EOL><INDENT>raise NotImplementedError("<STR_LIT>")<EOL><DEDENT>ncores = kwargs.pop('<STR_LIT>', <NUM_LIT:8>)<EOL>return [self.mpiexec, '<STR_LIT>', str(ncores)]<EOL>
Return a list of the mpi command portion of the commandline.

        Only allows primitive mpi at the moment:
           *mpiexec* -n *ncores* *mdrun* *mdrun-args*

        (This is a primitive example for OpenMP. Override it for more
        complicated cases.)