Density-functional theory-symmetry-adapted intermolecular perturbation theory with density fitting:: A new efficient method to study intermolecular interaction energies -: art. no. 014103
Density-functional theory-symmetry-adapted intermolecular perturbation theory with density fitting:: A new efficient method to study intermolecular interaction energies -: art. no. 014103
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DOI：
10.1063/1.1824898
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发表时间：
2005-01-01
影响因子：
4.4
通讯作者：
Schütz, M
中科院分区：
文献类型：
--
作者：
Hesselmann, A;Jansen, G;Schütz, M
先前开发的DFT-SAPT方法，它结合了自适应分子间微扰理论（SAPT）与密度泛函理论（DFT）表示的单体，已实施通过使用密度拟合的两个电子对象。这种方法，称为DF-DFT-SAPT，规模与分子大小的五次方和三次方后，增加基组大小为一个给定的二聚体，从而大大降低了传统的DFT-SAPT方法的成本。密度拟合近似的准确性已被测试的乙炔二聚体。已经发现，由于密度拟合引起的相互作用能的误差在10（-3）kcal/mol以下，具有合适的辅助基组，因此比由于使用有限的原子轨道基组引起的误差小一个或两个数量级。对苯二聚体的三种主要结构，即T形、平行位移和三明治结构，采用增强的四重zeta质量基组进行了研究，结果表明DF-DFT-SAPT的计算结果优于二阶Moller-Plesset理论（MP2），和微扰三重激发(C)2005年美国物理学会。
The previously developed DFT-SAPT approach, which combines symmetry-adapted intermolecular perturbation theory (SAPT) with a density-functional theory (DFT) representation of the monomers, has been implemented by using density fitting of two-electron objects. This approach, termed DF-DFT-SAPT, scales with the fifth power of the molecular size and with the third power upon increase of the basis set size for a given dimer, thus drastically reducing the cost of the conventional DFT-SAPT method. The accuracy of the density fitting approximation has been tested for the ethyne dimer. It has been found that the errors in the interaction energies due to density fitting are below 10(-3) kcal/mol with suitable auxiliary basis sets and thus one or two orders of magnitude smaller than the errors due to the use of a limited atomic orbital basis set. An investigation of three prominent structures of the benzene dimer, namely, the T shaped, parallel displaced, and sandwich geometries, employing basis sets of up to augmented quadruple-zeta quality shows that DF-DFT-SAPT outperforms second-order Moller-Plesset theory (MP2) and gives total interaction energies which are close to the best estimates infered from combining the results of MP2 and coupled-cluster theory with single, double, and perturbative triple excitations. (C) 2005 American Institute of Physics.