How to rapid cooling by lammps

Dear Lammpers,

I would like to cool rapidly a melt under its melting point temperature to make a supercooled nonequilibrium liquid.

Therefore, I applied NVT command with a short run time of below 1000 step(dt=5 fs) in order to be sure that equilibrium cannot be accessed. However, even in such small time period, monitoring melt temperature shows that temperature decreases rapidly to the desired under-cooled but I am not pretty sure that the undercooled melt is in equilibrium condition at this temperature or not?!

I think I should check potential energy of the melt at the desired under-cooled temperature after to equilibrium in order to understand whether the supercooled melt is in the equilibrium condition or not.

Actually, we need a supercooled melt in nonequilibrium condition.