According to https://geant4.web.cern.ch, Geant4 is a Toolkit for the simulation of the passage of particles through matter. which means that it is NOT a program that can be double-clicked and run ...

add geant4-v11.3.0**-install** to instalation folder (To not all files stay in same root folder) ADD CMAKE_ISNTALL_PREFIX your folder /home/clayton/Geant4/geant4-v11 ...