[lammps-users] oxygen in Reax

Hi, guys,

I ran Reax in LAMMPS for silicon and oxygen. I simply placed a Si cluster in the center of simulation box with oxygen molecules surrounding it.
Esemble is fixed as NVT for 1000K and timstep is 0.25 fs. After 10000 steps, the oxygen molecules are still 'frozen', i.e. no visible motion.
but with several bonding formed with atoms on proximity surface of silicon cluster. I assign the distance between O2 molecules at about 5 angtrom.
Is it the cause, i.e. beyond the force range of the Reax? I could squeeze the molecules tighter, but not what I want.

Sorry for this thoughtless question and any response will be apprieciated.

The reax page discusses cutoffs - the default is 10 Angs.
If you dump forces you will see if they are 0.0 or just small.