Local explicitly correlated coupled-cluster methods: Efficient removal of the basis set incompleteness and domain errors
Local explicitly correlated coupled-cluster methods: Efficient removal of the basis set incompleteness and domain errors
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DOI：
10.1063/1.3160675
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发表时间：
2009-06-28
影响因子：
4.4
通讯作者：
Werner, Hans-Joachim
中科院分区：
文献类型：
--
作者：
Adler, Thomas B.;Werner, Hans-Joachim
我们提出了一种显式相关的局部 LCCSD-F12 方法，其中基集不完整性误差以及将虚拟轨道空间截断为特定对局部域所引起的误差都得到了极大的减少。这是通过包含仅与特定对的配置空间正交的显式相关项来实现的。因此，域外激励的贡献由显式相关项隐式地解释。事实证明，对于一组 54 个反应，使用新的 LCCSD-F12 方法和三 zeta 基组计算的反应能量与传统 CCSD 完整基组结果的偏差最多为 2.5 kJ/mol（RMS：0.6 kJ/mol）。局部近似应该能够实现计算成本与分子尺寸的线性缩放。
We propose an explicitly correlated local LCCSD-F12 method in which the basis set incompleteness error as well as the error caused by truncating the virtual orbital space to pair-specific local domains are strongly reduced. This is made possible by including explicitly correlated terms that are orthogonalized only to the pair-specific configuration space. Thus, the contributions of excitations outside the domains are implicitly accounted for by the explicitly correlated terms. It is demonstrated for a set of 54 reactions that the reaction energies computed with the new LCCSD-F12 method and triple-zeta basis sets deviate by at most 2.5 kJ/mol from conventional CCSD complete basis set results (RMS: 0.6 kJ/mol). The local approximations should make it possible to achieve linear scaling of the computational cost with molecular size.