Energy conservation ENUC

Dear Fluka experts,
in a previous post we have already discussed momentum conservation, which I was able to prove for my simulation. Now I am wondering how to show that 4-momentum is conserved - thus missing energy conservation.
Is there any way to also check this on single event basis? Currently I am not reaching energy conservation, as the ID of the recoiling nucleus is missing. I did see that in resnuc.inc there is no direct particle ID for the recoiling nucleus. But since I use the kinetic energy of the recoiling particles, the mass is needed to calculate energy conservation.
At the moment I take the kinetic energy of all secondaries, add their masses and then subtract the total energy of the incoming beam particle.
Is there something I am missing? Or a simpler way?
I would be very thankful for some help,
kind regards
Laney

mgdraw_empty.f (10.4 KB) is a reworked version of the user routine previously made available, where total energy (kinetic + mass) has now been added.
Note that resnuc.inc provides the mass number and atomic number of the target nucleus (IBTAR and ICHTAR), allowing one to calculate its mass (ETAR in the routine), as well as the total energy of the residual ( = recoiling) nucleus (ERES), in addition to IBRES, ICRES, EKRES, …

Thank you very much!