[mod4 (modulepath)]$ module purge
[mod4 (modulepath)]$ module load openmpi/3.1
ERROR: Unable to locate a modulefile for 'openmpi/3.1'
[mod4 (modulepath)]$ module list
No Modulefiles Currently Loaded.
[mod4 (modulepath)]$ module purge
[mod4 (modulepath)]$ module load gcc/8.2.0
[mod4 (modulepath)]$ module load openmpi
[mod4 (modulepath)]$ module list
Currently Loaded Modulefiles:
 1) gcc/8.2.0   2) openmpi/3.1
[mod4 (modulepath)]$ mpirun
mpirun (openmpi/3.1, gcc/8.2.0)
