I have 2 surfaces interacting. I want the top surface to move at a
constant velocity. Is there a command to keep the velocity constant
throughout the simulation? Also I would like to calculate the forces on
each atom of the bottom surface from all of the atoms on the top
surface. (i.e., what are the forces on atom 1 of molecule A as it
interacts with all the atoms on molecule B?). Is there currently a way
to calculate this?