In this Letter we reinterpret the widely-used Steele 10-4-3 potential for a gas molecule interacting with a planar surface, and derive analogous potentials for adsorption in cylindrical and spherical pores. These new potentials correctly recover the Steele result in the limit of infinite pore radius, a useful improvement over existing models. In calculations of of argon adsorption via density functional theory the new cylindrical Steele potential gives markedly different behavior than existing potentials, due to differences in both the strength and shape of the fluid-surface interaction. The new potentials are more realistic in design and no more complex or computationally expensive to evaluate. They should therefore be preferred, especially in studies where comparison with planar substrates are made. Lastly, we discuss extension of this approach to more complicated pore geometries, yielding a family of Steele-like potentials that all satisfy the correct planar limit.
Citation: Journal of Physical Chemistry Letters
Pub Type: Journals
molecular modeling, adsorption, fluid-substrate interaction, lennard-jones potential, steele potential