I am doing some MD simulations on silicon nanowires which are cut from bulk silicon. There are some open bonds across the surface because of that. I used Stillinger weber potential to model the system. I ran NVT for a long time(2 nanoseconds using 1 fs timestep) and then shifted it to NVE. But the temperature of the system is increasing, even though i didn’t do anything to the system other than shifting ensemble. Do u have any thoughts in this regard?