To run, GEM needs the configuration files (short "config" files) listed below, which all need to be in a directory called "config directory". To make the exchange of these files easier between different users, I suggest we all keep similar "base" directory structures. Suggestion:

    ~/gem/version/Configs/...

For 'version' put one of the following:

    v_4.8.12.u   (GEM4.8)
    v_5.0.0   (GEM5.0)

Whenever you have problems with a simulation, let me know what the problem seems to be and where I can find your config files!

These are the needed config files:

configexp.cfg

gem_settings.nml  

outcfg.out  

physics_input_table

CLASS_input_table  (only GEM 5)