In the above mentioned constant temperature MD studies of gaseous CO 2 , within carbon nanotubes, classical Lennard-Jones (LJ) potentials were used to describe the particle-particle interaction and the particle-wall interaction. The lone two particle LJ interaction is insufficient to restrain a gaseous molecule with transnational kinetic energies at the given constant temperature. However, by using an analytic approach, where the entire energetic influence of the curved pore wall is taken into account, it is shown how the essential features in the density layering phenomenon, as predicted in the simulation studies, can be confirmed.