Ab initio calculation of the electronic structures of the 3Phi ground and 5Phi excited states of CoH.
Ab initio calculation of the electronic structures of the 3Phi ground and 5Phi excited states of CoH.
复制标题
CoH 3Phi 基态和 5Phi 激发态电子结构的从头计算。
DOI：
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发表时间：
2007
影响因子：
4.4
通讯作者：
Tsuneo Hirano
中科院分区：
文献类型：
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作者：
M. Tomonari;Rei Okuda;U. Nagashima;Kiyoshi Tanaka;Tsuneo Hirano
采用多参考单激发和双激发组态相互作用(MR-SDCI)+戴维森校正(Q)计算和尺寸一致多参考耦合对近似（MRCPA）计算，研究了CoH分子的电子地3Phi和低5Phi电子激发态的电子结构和光谱常数。使用slater型基函数在Cinfinityv对称下进行计算。电子基态被确认为3Phi态。研究发现，至少需要四种参考配置才能正确描述MR-SDCI+Q水平上的接地3Phi状态，而5Phi状态可以用一种参考配置来很好地描述，即Hartree-Fock配置。讨论了低自旋3Phi态比高自旋5Phi态更大的动态电子相关性。通过MR-SDCI+Q方法得到的光谱常数，即平衡键长（re）、谐波频率（omegae）和激发能与实验值有很好的对应关系。MRCPA计算得到的re值略短于实验值，但改进了ω和激发能，使它们非常接近实验值。
The electronic structures and the spectroscopic constants of the electronic ground 3Phi and low-lying 5Phi electronic excited states of the CoH molecule were studied by multireference single and double excitation configuration interaction (MR-SDCI)+Davidson's correction (Q) calculations and size-consistent multireference coupled pair approximation (MRCPA) calculations. Calculations were performed under Cinfinityv symmetry using Slater-type basis functions. The electronic ground state was confirmed to be the 3Phi state. It was found that at least four reference configurations were needed to describe the ground 3Phi state correctly at the MR-SDCI+Q level, while the 5Phi state can be described well by one reference configuration, namely, the Hartree-Fock configuration. Larger dynamical electron correlation for the low-spin 3Phi state than that for the high-spin 5Phi state is discussed. Spectroscopic constants, i.e., equilibrium bond lengths (re), harmonic frequency (omegae), and excitation energy, obtained by the MR-SDCI+Q method showed good correspondence with experimental values. MRCPA calculations gave a slightly shorter value for re than experimental values, but improved omegae and the excitation energy bringing them very close to experimental values.