The difference between fluka and geant4/Mcnp6?

the deposited energy is scored using the command usrbin:
USRBIN 12. EM-ENRGY -31. TARGET TEDepo
USRBIN TARGET &

the result is 0.377027 MeV/primary, when what(2)=ENERGY, the result is almostly same.
but the value is 0.437818 MeV/primary and
0.440371 MeV/primary.
it seems the result using fluka is wrong.
To this issue, the other command not usrbin should be used?

The USRBIN card is the right choice. The fact that the result is different from other codes, which are in turn different between them, does not automatically imply that it’s wrong. In particular, I’d first check (for all codes) its dependence on the electromagnetic transport thresholds, which in FLUKA can be adjusted according to the physics needs of the problem by means of the EMFCUT card. In general, the lower the thresholds the more accurate the result (low energy particles can actually leave the target, not depositing all their energy there), but also the longer the CPU time.

@ Francesco Cerutticeruttif, thanks, i will check the codes.