Chemistry and Chemical Biology, School of Natural Sciences, University of California, Merced, 5200 North Lake Road, Merced, California 95343, USA.
J Chem Phys. 2013 Dec 7;139(21):214109. doi: 10.1063/1.4832325.
In the development and application of dispersion-corrected density-functional theory, the effects of basis set incompleteness have been largely mitigated through the use of very large, nearly-complete basis sets. However, the use of such large basis sets makes application of these methods inefficient for large systems. In this work, we examine a series of basis sets, including Pople-style, correlation-consistent, and polarization-consistent bases, for their ability to efficiently and accurately predict non-covalent interactions when used in conjunction with the exchange-hole dipole moment (XDM) dispersion model. We find that the polarization-consistent 2 (pc-2) basis sets, and two modifications thereof with some diffuse functions removed, give performance of comparable quality to that obtained with aug-cc-pVTZ basis sets, while being roughly 12 to 23 times faster computationally. The behavior is explained, in part, by the role of diffuse functions in recovering small density changes in the intermolecular region. The general performance of the modified basis sets is tested by application of XDM to standard intermolecular benchmark sets at, and away from, equilibrium.
在开发和应用色散校正密度泛函理论时，通过使用非常大的、几乎完整的基组，在很大程度上缓解了基组不完整的影响。然而，对于大体系来说，使用如此大的基组会导致这些方法的应用效率低下。在这项工作中，我们研究了一系列基组，包括 Pople 风格、相关一致和极化一致基组，考察它们在与交换空穴偶极矩（XDM）色散模型结合使用时预测非共价相互作用的能力。我们发现，极化一致 2（pc-2）基组及其两个修改版本（去掉了一些弥散函数）的性能与 aug-cc-pVTZ 基组相当，而计算速度快约 12 到 23 倍。这种行为部分归因于弥散函数在恢复分子间区域小的密度变化方面的作用。通过在平衡和非平衡条件下将 XDM 应用于标准的分子间基准集，测试了修改后的基组的一般性能。
