Accurate molecular integrals and energies using combined plane wave and Gaussian basis sets in molecular electronic structure theory
Accurate molecular integrals and energies using combined plane wave and Gaussian basis sets in molecular electronic structure theory
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DOI：
10.1063/1.1467901
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发表时间：
2002-04
影响因子：
4.4
通讯作者：
L. Fusti-Molnar;P. Pulay
中科院分区：
文献类型：
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作者：
L. Fusti-Molnar;P. Pulay
本文介绍了平面波基组在精确分子计算中的应用的两项进展。 (1) 引入了截断到有限范围的库仑算子动量空间表示的解析公式。使用该算子，可以精确消除分子与其周期性复制品之间的相互作用。给出了证明我们方案准确性的例子。使用高质量平面波基础的计算产生的变分总 SCF 能量低于使用简单二电子系统的 cc-pvQZ 基础获得的能量。 (2)提出了一种新的混合基增强平面波全电子方法——平面波核高斯方法，它扩展了平面波中分子轨道的价态部分，以及非重叠紧致高斯中的类核部分。已经导出了必要的混合高斯/平面波电子斥力积分的解析方程。使用这种增强基组，我们能够将小分子的高斯基 Hartree 能量再现到几 μE h 之内。
This paper introduces two developments for the application of plane wave basis sets for accurate molecular calculations. (1) An analytical formula is introduced for the momentum space representation of a Coulomb operator truncated to a finite range. Using this operator, interactions between the molecule and its periodic replicas can be exactly eliminated. Examples demonstrating the accuracy of our scheme are given. Calculations using a good-quality plane wave basis yield variational total SCF energies which are lower than those obtained with the cc-pvQZ basis for simple two-electron systems. (2) A new mixed-basis augmented plane wave all-electron method, the plane wave core Gaussian method has been developed which expands the valence part of the molecular orbitals in plane waves, and the corelike part in nonoverlapping compact Gaussians. Analytic equations have been derived for the necessary mixed Gaussian/plane wave electron repulsion integrals. Using such augmented basis set, we were able to reproduce the Gaussian-basis Hartree energies of small molecules to within a few μE h .