Dear lammps user,
I ma trying to move group of atom towards center of tube for a certain time step and away from the tube after that for some time step. But I couldn't figure out the way of giving Vx Vy in fix command that will do this work. Can you please suggest me some way so that can a can apply contarction and expansion of a cylindrical tube about its vertical axis using fix move command.
in the image below I am trying to move the yellow particle radially.