Geant4 Manual Access

You aren't supposed to "run" the manual like a script. You are supposed to inherit from classes ( G4VUserDetectorConstruction , G4VUserPhysicsList ). The manual is telling you which virtual functions to override.

Use it to look up specific classes ( G4RunManager ) or specific physics models. For tutorials, use the examples. For answers, use the mailing list. geant4 manual

It is over 1,000 pages of dense, technical, physics-heavy documentation. Newcomers often open it, search for "Hello World," find nothing, and close the tab in despair. You aren't supposed to "run" the manual like a script

But let’s be honest:

And when you finally get that G4Trajectory to draw a beautiful line through your detector, you will thank the manual—even if you just used it to find that one parameter name you forgot. use the examples. For answers