thanks a lot for your help.
After looking at the input script more carefully and testing several cases, I found that the command "fix Ther all thermal/conductivity 100 z 20" and "fix Visc all viscosity 100 x y 20" make the NVE simulation bad (non-conserved thermodynamic quantities). When I remove these fix command, the NVE simulation works well.
Could you tell me why such thing happens from these fix commands?
Sang-Pil Kim wrote: