Achieving High-Accuracy Intermolecular Interactions by Combining Coulomb-Attenuated Second-Order M酶ller鈥揚lesset Perturbation Theory with Coupled Kohn鈥揝ham Dispersion

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• 作者：Yuanhang Huang ; Matthew Goldey ; Martin Head-Gordon ; Gregory J. O. Beran
• 刊名：Journal of Chemical Theory and Computation
• 出版年：2014
• 出版时间：May 13, 2014
• 年：2014
• 卷：10
• 期：5
• 页码：2054-2063
• 全文大小：521K
• 年卷期：v.10,no.5(May 13, 2014)
• ISSN：1549-9626

文摘

The dispersion-corrected second-order M酶ller鈥揚lesset perturbation theory (MP2C) approach accurately describes intermolecular interactions in many systems. MP2C, however, expends much computational effort to compute the long-range correlation with MP2, only to discard and replace those contributions with a simpler long-range dispersion correction based on intermolecular perturbation theory. Here, we demonstrate that one can avoid calculating the long-range MP2 correlation by attenuating the Coulomb operator, allowing the dispersion correction to handle the long-range interactions inexpensively. With relatively modest Coulomb attenuation, one obtains results that are very similar to those from conventional MP2C. With more aggressive attenuation, one can remove just enough short-range repulsive exchange鈥揹ispersion interactions to compensate for finite basis set errors. Doing so makes it possible to approach complete basis set limit quality results with only an aug-cc-pVTZ basis, resulting in substantial computational savings. Further computational savings could be achieved by reformulating the MP2C algorithm to exploit the increased sparsity of the two-electron integrals.