Implications of the complete basis set limit in valence bond theory: a case study of molecular hydrogen
Implications of the complete basis set limit in valence bond theory: a case study of molecular hydrogen
复制标题
价键理论中完整基组极限的含义：分子氢的案例研究
DOI：
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发表时间：
2016
影响因子：
1.7
通讯作者：
R. Havenith
中科院分区：
文献类型：
--
作者：
B. Duke;R. Havenith
使用较大的基组，以接近完整的基础限制，现在常见的量子化学，是第一次适用于一系列的价键功能的最简单的情况下，分子氢。由于在原子核附近难以获得正确的尖点，能量的良好收敛是缓慢的，但它是重要的。轨道的形式收敛得快得多，导致价键轨道的轻微扭曲和增强的重叠，无论基组是否被限制为以每个价键轨道的一个原子为中心的基函数或允许充分使用基组。这模糊了这两种方法之间的区别，并表明基组限制在完整的基组限制中是站不住脚的。此外，它支持一般使用的全基主张在自旋耦合和广义价键方法。
The use of larger basis sets to approach the complete basis limit, now common in quantum chemistry, is applied for the first time to a range of valence bond functions for the simplest case of molecular hydrogen. Good convergence of the energy is slow due to difficulty in getting a correct cusp near the nuclei, but it is significant. The form of the orbitals converges much faster, leading to a slight distortion of the valence bond orbitals and an enhanced overlap, irrespective whether the basis set is restricted to basis functions centred on one atom for each valence bond orbital or the full use of the basis set is allowed. This blurs the distinction between these two approaches and shows that basis set restrictions are not tenable in the complete basis set limit. Furthermore, it supports the general use of the full basis as advocated in the spin-coupled and generalised valence bond methods.