t print MPI task id and Thread id
               If run with OpenMP threading enabled OMP_NUM_THREADS > 1
               there will be a line per MPI task and Thread.

 -F or -2    : Add columns to tell first MPI task on a node and and the
               numbering of tasks on a node. (Hint: pipe this output in
               to sort -r

 -a          : Print a listing of the environmental variables passed to
               MPI task. (Hint: use the -l option with SLURM to prepend MPI
               task #.)

