Beyond Born–Mayer: Improved Models for Short-Range Repulsion in ab Initio Force Fields
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- 作者：Mary J. Van Vleet ; Alston J. Misquitta ; Anthony J. Stone ; J. R. Schmidt
- 刊名：Journal of Chemical Theory and Computation
- 出版年：2016
- 出版时间：August 9, 2016
- 年：2016
- 卷：12
- 期：8
- 页码：3851-3870
- 全文大小：882K
- 年卷期：0
- ISSN：1549-9626
文摘
Short-range repulsion within intermolecular force fields is conventionally described by either Lennard-Jones (A/r12) or Born–Mayer (A exp(−Br)) forms. Despite their widespread use, these simple functional forms are often unable to describe the interaction energy accurately over a broad range of intermolecular distances, thus creating challenges in the development of ab initio force fields and potentially leading to decreased accuracy and transferability. Herein, we derive a novel short-range functional form based on a simple Slater-like model of overlapping atomic densities and an iterated stockholder atom (ISA) partitioning of the molecular electron density. We demonstrate that this Slater–ISA methodology yields a more accurate, transferable, and robust description of the short-range interactions at minimal additional computational cost compared to standard Lennard-Jones or Born–Mayer approaches. Finally, we show how this methodology can be adapted to yield the standard Born–Mayer functional form while still retaining many of the advantages of the Slater-ISA approach.