Hi,

I placed few C60 fullerene molecule within a crystal lattice and put an external force condition (raising the temperature in this case) to see how molecules are moving under different condition.

In this simulation, I want to consider only inter-molecular potential (van-der waals, columb), assumming the C60 molecule itself is quite rigid and all the bond angles and distance will not change - only position of molecules is changing.

I used forcite anneal dialog to see shortly. If you look at the C60 anneal.xtd file, the bond within c60 molecule was distorted. I know from the experiment that the molecule is just moving, there is no distortion or change in bond length within a molecule.

Is there a way to simulate this situation properly?
I've attached my simulation file as well.

Regards,
Byeongseop Song.