Dear LAMMPS users
I am trying to determine the friction forces contributed by water molecules moving past a nano-tube. The nanotube is essentially at rest with no initial forces. When a water molecule collides with the walls of the nanotube, I intend to record this impact force. Since I wish to allow the nanotube walls to be able to flex, I want to sum up only the C-C AIREBO interaction forces (both the REBO and LJ C-C forces), since this should equate with the collision forces of the water molecules.
I understand that LAMMPS only allows the computation of the total force. By summing up the total forces on the nanotube, I would obtain 0 force. Can any LAMMPS user suggest where I can modify the code to extract the sum of the C-C AIREBO interaction forces? I have looked into the pair-AIREBO.cpp file but am not sure where exactly to extract the appropriate forces. I am using the AIREBO potential with LJ but without torsion.
Appreciate any suggestions.
Huck Beng, Chew