Accurate Intermolecular Interactions at Dramatically Reduced Cost: XPol+SAPT with Empirical Dispersion
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- 作者：Ka Un Lao ; John M. Herbert
- 刊名：The Journal of Physical Chemistry Letters
- 出版年：2012
- 出版时间：November 15, 2012
- 年：2012
- 卷：3
- 期：22
- 页码：3241-3248
- 全文大小：478K
- 年卷期：v.3,no.22(November 15, 2012)
- ISSN：1948-7185
文摘
An efficient, monomer-based electronic structure method is introduced for computing noncovalent interactions in molecular and ionic clusters. It builds upon our explicit polarization plus symmetry-adapted perturbation theory approach, XPol+SAPT (XPS), but replaces the problematic and expensive sum-over-states dispersion terms with empirical potentials. This modification reduces the scaling from to with respect to monomer size and also facilitates the use of Kohn鈥揝ham density functional theory (KS-DFT) as a low-cost means to capture intramolecular electron correlation. The accuracy of the resulting method [XPS(KS)+D], in conjunction with a double-味 basis set, is superior to MP2-type methods extrapolated to the basis-set limit, with a mean unsigned error of 0.27 kcal/mol for the S66 data set. XPS(KS)+D yields accurate potential energy curves for a variety of challenging systems. As compared to traditional DFT-SAPT methods, it removes the limitation to dimers and extends SAPT-based methodology to many-body systems.