There are commands /run/storeRandomNumberStatus Frequency /run/restoreRandomNumberStatus FileName These commands save and restore the state of the random number engine in G4. However an attempt to use the first command in Geant 4.1.1 with any Frequency (-2,-1,1,2) leads to ... /run/storeRandomNumberStatus -2 /run/beamOn 1 ### Run 0 start. Energies per event for Run #0(10 GeV e-) Segmentation fault (core dumped) This has been confirmed both in the LAR simulation that we run at Nevis, and in Example N02. We therefore assume that this problem is not particular to our simulation code. I've verified that we're running CLHEP 1.4.0. I've traced the problem, and I believe it may arise in $CLHEP_BASE_DIR/Random/Random.cc (since the output file is created, but no bytes are written to it before the seg fault).
If running on a Linux system, please make sure that both CLHEP and G4 libraries have been compiled using the same OS/compiler version. A problem of this kind arises if for example you built CLHEP with RedHat 5.1, while Geant4 with RedHat 6.X. It is due to a binary incompatibility between the standard libC in the two systems.