Explicitly correlated coupled cluster methods with pair-specific geminals
Explicitly correlated coupled cluster methods with pair-specific geminals
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DOI：
10.1080/00268976.2010.526641
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发表时间：
2011-02
影响因子：
1.7
通讯作者：
H. Werner;G. Knizia;F. Manby
中科院分区：
文献类型：
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作者：
H. Werner;G. Knizia;F. Manby
提出了轨道对特定的斯莱特型双子结构的显式关联MP2-F12和CCSD(T)-F12方法。使用Ten-NO的固定振幅ansatz，对于核-核、核-价和价-价对，可以选择不同指数的斯莱特配位函数。这考虑到了关联空穴的不同大小，并在内壳轨道关联时带来了更好的结果。与使用单双基元的相应计算相比，这种方法的复杂性和额外的计算成本都很小。对以d轨道为核的Br2、As2、Ga2、Cu2、GaClCuClCuBr3的光谱性质，证明了该方法具有较高的精确度。
Explicitly correlated MP2-F12 and CCSD(T)-F12 methods with orbital-pair-specific Slater-type geminals are proposed. The fixed amplitude ansatz of Ten-no is used, and different exponents of the Slater geminal functions can be chosen for core–core, core–valence, and valence–valence pairs. This takes care of the different sizes of the correlation hole and leads to improved results when inner-shell orbitals are correlated. The complications and the extra computational cost as compared to corresponding calculations with a single geminal are minor. The improved accuracy of the method is demonstrated for spectroscopic properties of Br2, As2, Ga2, Cu2, GaCl, CuCl, and CuBr, where the d-orbitals are treated as core.