This analytic result is compared with an MD study of CO 2 gas within a (40, 40) carbon nanotube. The expression for the potential describes well the nature of the outer density layer that appears upon the first insertion of gaseous particles within the tube. Both the beginning and ending radial coordinate for the outer high density layer predicted by this analytic result agree with those reported in the cited MD study. Additionally, results from this work predict that a boundary potential well, which serves to form the outer layer, has a maximum well depth of approximately 1.7 times that of the mean thermal translational energies for the gaseous particles at the temperature in question thus confirming the prediction of the MD study for there being a stable outer gaseous layer.