The problem is that LAMMPS is only available in toolchains which include ParaStationMPI.
The problem is that LAMMPS is only available in particular toolchain which includes Stages/2022, GCC/11.2.0, ParaStationMPI/5.5.0-1.
We could simply reload the MPI module rather than having to reload the entire toolchain, but this can sometimes come with unintended consequences, where what is loaded in a `module load` command is not necessarily unloaded while swapping modules.
We could simply reload the MPI module rather than having to reload the entire toolchain, but this can sometimes come with unintended consequences, where what is loaded in a `module load` command is not necessarily unloaded while swapping modules.
For this reason, we also do not recommend using the `module unload` command, although it is available.
For this reason, we also do not recommend using the `module unload` command, although it is available.
We would recommend to unload (almost) all modules and start with a fresh environment, using `module purge`:
We would recommend to unload (almost) all modules and start with a fresh environment, using `module purge`:
```
```
$ module purge
$ module purge
$ module load GCC
$ module load Stages/2022
$ module load ParaStationMPI
$ module load GCC/11.2.0
$ module load ParaStationMPI/5.5.0-1
$ module load LAMMPS
$ module load LAMMPS
```
```
The `module` command is part of the Lmod software package.
The `module` command is part of the Lmod software package.
It comes with its own help document which you can access by running `module help` and a [user guide is available online](https://lmod.readthedocs.io).
It comes with its own help document which you can access by running `module help` and a [user guide is available online](https://lmod.readthedocs.io).