[lammps-users] ReaxFF Simulation Si: Energy Conservation Problem

Hi Aidan,

Thanks again for your input on the carbon nanotube simulations. I am also interested in using ReaxFF to simulate Si-based materials.

I ran two simulations on a Si block of dimensions 10x2x10 unit cells: using ReaxFF and Stillinger-Weber(SW) force fields. I ran both simulations for 200 times steps. The simulation using SW is stable. But the ReaxFF system is unstable. The temperature rises from 0K to ~31,000K in 200fs. I tried reducing the time-step to 0.0025fs (from 0.025fs) and it is still unstable.

I've a attached a movie showing a comparison between the two simulations. Could you have a look at my output files(attached)? Please let me know if you have any suggestions. Thanks again for your help!

Nicholas J. Lee

Si_block_SW_vs_ReaxFF.zip (10 MB)