Thank you for the answer, Steve! I have understood the explanation you gave which must be the reason
causing the collapse. However, I still don't understand why a stable system can
become unstable after such a long simulation time. Especially, the system and parameters used
seems not inappropriate.
To my understanding, in a real atomic system the covalent bonding is almost the strongest
interaction, which means the absolution change in the bond distance should be very small.
And it should be fast converged. Even the nonbonded interaction should have converged as
monitored by the intra- and inter- molecular energies. How can "a bad physics" happen in the
middle of a simulation? I can show the thermo output if somebody is interested. It's really like
a comet hitting the earth, a peaceful world destroyed in a second.
Anyway, I will investigate this when I have time. I also noticed somebody reported this kind of
problem happens in a parallel job but not in a serial job. I give my report later. But right now I
urgently need some result, but I was hindered by this problem. Move to another program temporarily
I'd also like to know if somebody has met a similar case, the simulation crashed not in the beginning but
after a long simulation time?
Steve Plimpton wrote: