I want to build a cylindrical shell boundary with periodic boundary
condition in axis, which models a narrow, infinitely long tube.I don't know
how to do with Lammps command. I hope some person can help me. It is
loooong ago a colleague of mine did MD studies of electrolytes through
small nano-tubular structures and he found that there are two ways to
build such a confinement: you build a tubular structure from
lennard-jones or similar potentials (you didn't specify what interactions
the tube should have with what is inside) and fix their positions in
space. you can write a small script or program to generate them.
the second option is to apply a cylindrical wall potential. that
you'd have to implement. ...and again it is all a question of what
kind of interactions of your particles in the tube you want to have
with the wall. if you want to just have repulsion, you can implement
a repulsive morse or lennard-jones, which is pretty straighforward.
hope that helps,