title: Beyond Born-Mayer: Improved Models for Short-Range Repulsion in ab Initio Force Fields.
abstract: Short-range repulsion within intermolecular force fields is conventionally described by either Lennard-Jones (A/r(12)) 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.
authors.affiliation: Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Van Vleet
authors.affiliation: Department of Physics and Astronomy, Queen Mary University of London , London E1 4NS, United Kingdom.
authors.forename: Alston J
authors.initials: AJ
authors.lastname: Misquitta
authors.affiliation: Department of Chemistry, University of Cambridge , Cambridge CB2 1EW, United Kingdom.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Stone
authors.affiliation: Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: J R
authors.initials: JR
authors.lastname: Schmidt