Chemical and Biochemical Reference Data Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
J Chem Phys. 2011 Aug 28;135(8):084703. doi: 10.1063/1.3626804.
Simplified fluid-substrate interaction models derived from the Lennard-Jones potential are widely used in the simulation of gas physisorption phenomena. In this paper, we reinterpret the well known Steele 10-4-3 potential for a gas molecule interacting with a planar surface, and use the resultant scheme to derive new potentials for cylindrical and spherical pore geometries. These new potentials correctly recover the Steele result in the limit of infinite pore radius, a useful improvement over existing models. We demonstrate the new cylindrical Steele 10-4-3 potential in calculations of argon adsorption via fluid density functional theory. This potential yields markedly different adsorption behavior than existing cylindrical potentials, which follow from small but significant differences in both the strength and the shape of the fluid-surface interaction. These differences cannot be fully reconciled simply by reparameterizing (scaling) the existing models; the new potential is more realistic in design, and is especially to be preferred in studies where comparison with planar substrates is made. Finally, we discuss extensions of this approach to more complicated pore geometries, yielding a family of Steele-like potentials that all satisfy the correct planar limit.
基于 Lennard-Jones 势能的简化流体-基底相互作用模型广泛应用于气体物理吸附现象的模拟。在本文中，我们重新解释了著名的 Steele 10-4-3 势能，用于气体分子与平面表面相互作用，并使用所得方案推导出用于圆柱形和球形孔几何形状的新势能。这些新的势能在无限孔半径的极限下正确地恢复了 Steele 的结果，这是对现有模型的一个有用的改进。我们通过流体密度泛函理论计算展示了新的圆柱形 Steele 10-4-3 势能在氩气吸附中的应用。与现有圆柱形势能相比，这种新的势能表现出明显不同的吸附行为，这源于流体-表面相互作用的强度和形状上的微小但显著的差异。这些差异不能通过简单地重新参数化（缩放）现有模型来完全调和；新的势能在设计上更加现实，特别是在与平面基底进行比较的研究中更受欢迎。最后，我们讨论了这种方法对更复杂的孔几何形状的扩展，得到了一系列满足正确平面极限的 Steele 类似势能。
