You have two MPI versions installed:
Code: Select all
mpi/mpich-x86_64 mpi/openmpi-x86_64 (D)
The openmpi-x86_64 seems to be set explicitly as default.
Default means that if one does
Then current shell's environment is modified to find the openmpi-x86_64.
If you do
then you get access to mpich.
It used to be common to
source config
use program
but then you have the config in environment and doing something else requires a new shell session.
The
module add is essentially
source config, but with most modules you can
module rm mpi/mpich-x86_64 or
module purge to "undo the source", revert environment.
Environment modules has been in use in HPC clusters quite a while now.
Software Collections' (SCL, more prevalent in CentOS 7)
scl does start a subshell with modified environment, rather than modifying env of current shell. SCL is similar to environment modules, but has different origin.