Explicitly correlated second-order perturbation theory calculations on molecules containing heavy main-group elements
Explicitly correlated second-order perturbation theory calculations on molecules containing heavy main-group elements
复制标题
含重主族元素分子的显式相关二阶微扰理论计算
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
W. Klopper
中科院分区：
文献类型：
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作者：
F. Bischoff;S. Höfener;Andreas Glöss;W. Klopper
Slater 型孪晶 (STG) 已被用作显式相关的双电子基函数，用于计算高斯原子轨道的各种单电子基组中的 N-As 和 Sb 的氢化物（以及 O-Se 和 F-Br 的氢化物，具有类似的但未报告的结果）。显式相关理论的性能已根据 STG 的指数进行了评估，例如，通过对各个对相关函数和对能量使用不同的指数。结果表明，指数为 $${gamma = 1.4 a_{0}^{-1}}$$ 的相关因子可以为价壳的 aug-cc-pVQZ 基组中的所有研究分子提供距基组限制 1% 以内的可靠结果，并在理论的对角轨道不变公式中使用 STG 的固定振幅。已经研究了相对论有效核心势（RECP）在显式相关二阶微扰理论中的使用。
Slater-type geminals (STGs) have been used as explicitly correlated two-electron basis functions for calculations on the hydrides of N–As and Sb (as well as on the hydrides of O–Se and F–Br with similar, not reported results) in various one-electron basis sets of Gaussian atomic orbitals. The performance of the explicitly correlated theory has been assessed with respect to the exponent of the STG, for example, by using different exponents for individual pair correlation functions and pair energies. It is shown that a correlation factor with an exponent of $${gamma = 1.4 a_{0}^{-1}}$$ can give reliable results within 1% from the basis-set limit for all investigated molecules in an aug-cc-pVQZ basis set for the valence shells, using fixed amplitudes for the STGs in a diagonal orbital-invariant formulation of the theory. The use of relativistic effective core potentials (RECPs) in explicitly correlated second-order perturbation theory has been investigated.