Dear LAMMPS community,

I want to simulate adsorption of any gas molecule on a zeolite by using fix gcmc. As you know, some gas molecules have dummy atoms in order to reproduce experimental values, such as dipole moment.

My question is how to model a gas molecule, for example 3-site nitrogen molecule, (two N atoms and a dummy atom between N atoms)?

Making null the mass of dummy atom does not work, and lammps gives an error because of the null mass of dummy atom.

Is it meaningful to set a sufficiently small number, for example 0.1, for dummy atom in lammps data file?

Does anyone have an idea to deal with the aforementioned problem?



Use a very, very small mass and fix rigid and it should work.