Hello everybody,

I have built a long polymer chain and after equilibration using Forcite modulus with COMPASS forcefield, I have displaced one of the chain ends and after each displacement I have got the force acting on the atoms on the displaced end. But I have a question about my script and will be appreciated if help me. Why the calculated forces on the atoms before and after displacement are the same? After displacement some of bonds and angles are stretched away from their equilibrium so it is expected to applied forces to atoms with larger values. But in my results in each step these two forces are equal. I am going to find the force-displacement curve for my process .Would you please guide me.

Best Regards

SJN