New users may not have MPI or Scalapack installed, or may have broken versions of those libraries. Although real work with Gemini benefits greatly from parallelism, we don't want to lose new users who get frustrated. Better to have their simulations successfully run, then they can get MPI working to speed up their runs.

This works with either autobuild Mumps or if a user separately installed Mumps with cmake -Dparallel=no option.