See the GEANT4 project page. To use GEANT4, you’ll use the module tool.

You can see what versions are available by using:

[me@login01 ~]$ module avail geant4

------------------------------ /opt/modulefiles -------------------------------
   geant4/10.7.1

Use "module spider" to find all possible modules and extensions.
Use "module keyword key1 key2 ..." to search for all possible modules matching
any of the "keys".

To load a specific version, you would use:

[me@login01 ~]$ module load geant4/10.7.1

while the "geant4" wildcard will load the default version, geant4-10.7.1 in this case.

You should now be able to run GEANT4 commands:

[me@login01 ~]$ which geant4.sh

/export/geant4/v10.7.1/bin/geant4.sh