Spin-Orbit Effects in Closed-Shell Heavy and Superheavy Element Monohydrides and Monofluorides with Coupled-Cluster Theory.
Spin-Orbit Effects in Closed-Shell Heavy and Superheavy Element Monohydrides and Monofluorides with Coupled-Cluster Theory.
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DOI：
10.1021/acs.jpca.5b11948
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发表时间：
2016-02
期刊：
影响因子：
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通讯作者：
Dong Gao;Zhanli Cao;Fan Wang
中科院分区：
文献类型：
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作者：
Dong Gao;Zhanli Cao;Fan Wang
本文计算了一组第六排超重元素单氟和单氟的键长和力常数。计算中采用了Kramers限制耦合团簇方法（KR-CC）和后自洽场处理方法（SOC-CC）。采用最近发表的相对论有效实势，用KR-CCSD（T）方法对超重元素分子进行了高精度的计算。研究了SOC对这些分子的键长和力常数的影响。电子关联效应在很大程度上受到SOC的影响。对于大多数第六排元素分子，SOC-CC的键长和力常数与KR-CC的键长和力常数非常一致。对于超重元素分子，SOC-CCSD的计算结果与KR-CCSD的计算结果基本一致，但111 F除外，而SOC-CCSD（T）的计算结果误差较大。当SOC和电子关联效应都相当大时，SOC-CC方法会遇到很大的误差。
Bond lengths and force constants of a set of closed-shell sixth-row and superheavy element monohydrides and monofluorides are calculated in this work. Kramers restricted coupled-cluster approaches (KR-CC) with spin-orbit coupling (SOC) included at the self-consistent field (SCF) level as well as CC approaches with SOC included in post-SCF treatment (SOC-CC) are employed in calculations. Recently published relativistic effective core potentials are employed, and highly accurate results for superheavy element molecules are achieved with KR-CCSD(T). SOC effects on bond lengths and force constants of these molecules are investigated. Effects of electron correlation are shown to be affected by SOC to a large extent for some superheavy element molecules. Bond lengths and force constants with SOC-CC agree very well with those of KR-CC for most of the sixth-row element molecules. As for superheavy element molecules, SOC-CCSD is able to afford results that are in good agreement with those of KR-CCSD except for 111F, while the error of SOC-CCSD(T) is more pronounced. Large error would be encountered with SOC-CC approaches for molecules when both SOC and electron correlation effects are sizable.