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Comprehensive Analysis of the Neglect of Diatomic Differential Overlap Approximation
Journal of Chemical Theory and Computation ( IF 5.5 ) Pub Date : 2018-09-06 00:00:00 , DOI: 10.1021/acs.jctc.8b00601
Tamara Husch 1 , Markus Reiher 1
Affiliation  

Many modern semiempirical molecular orbital models are built on the neglect of diatomic differential overlap (NDDO) approximation. An in-depth understanding of this approximation is therefore indispensable to rationalize the success of these semiempirical molecular orbital models and to develop further improvements on them. The NDDO approximation provides a recipe to approximate electron–electron repulsion integrals (ERIs) in a symmetrically orthogonalized basis based on a far smaller number of ERIs in a locally orthogonalized basis. We first analyze the NDDO approximation by comparing ERIs in both bases for a selection of molecules and for a selection of basis sets. We find that the errors in Hartree–Fock and second-order Møller–Plesset perturbation theory energies grow roughly linearly with the number of basis functions. We then examine different approaches to correct for the errors caused by the NDDO approximation and propose a strategy to directly correct for them in the two-electron matrices that enter the Fock operator.

中文翻译:

忽略了双原子微分重叠近似的综合分析

许多现代的半经验分子轨道模型都是建立在忽略双原子微分重叠(NDDO)近似的基础上的。因此,对这种近似的深入理解对于合理化这些半经验分子轨道模型的成功并对其进行进一步的改进是必不可少的。NDDO近似提供了一种基于局部正交的ERI数量少得多的,在对称正交的基础上近似电子-电子排斥积分(ERI)的方法。我们首先通过比较两种碱基的ERI来选择分子和选择基集来分析NDDO近似值。我们发现,Hartree-Fock和二阶Møller-Plesset微扰理论能量的误差随基函数的数量大致线性增长。
更新日期:2018-09-06
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