Optimized accurate auxiliary basis sets for RI-MP2 and RI-CC2 calculations for the atoms Rb to Rn
Optimized accurate auxiliary basis sets for RI-MP2 and RI-CC2 calculations for the atoms Rb to Rn
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DOI：
10.1007/s00214-007-0250-5
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发表时间：
2007-04-01
影响因子：
1.7
通讯作者：
Klopper, Wim
中科院分区：
文献类型：
--
作者：
Hellweg, Arnim;Haettig, Christof;Klopper, Wim
在量子化学计算中引入电子排斥积分的恒等式分解(RI)近似，除了轨道基外，还需要所谓的辅助基组或拟合基组。我们在这里报道了为最近出版的(Weigend和Ahlrichs Phys Chem Chem Phys，2005，7,3297-3305)Rb-Rn原子(除稀土以外)的分裂、三Zeta和四Zeta价性质的分段压缩高斯基组的二阶M Phi ller-Plesset微扰理论优化的辅助基组。这些基组设计用于小核有效核势，包括标量相对论修正。因此，现在可以用二阶M Phi ller-Plesset微扰理论(MP2)和相关方法对含有从H到Rn的元素的分子进行精确的恒等式分解计算。对代表每种元素共同氧化状态的385个中小分子的测试集，评估了RI近似的误差，并与基于高精度显式相关MP2-R12计算估计的单电子基组误差进行了比较。使用所报告的辅助基组，MP2关联能的RI误差通常比单电子基组的误差小两个数量级，与原子在元素周期表中的位置无关。
The introduction of the resolution-of-the-identity (RI) approximation for electron repulsion integrals in quantum chemical calculations requires in addition to the orbital basis so-called auxiliary or fitting basis sets. We report here such auxiliary basis sets optimized for second-order M phi ller-Plesset perturbation theory for the recently published (Weigend and Ahlrichs Phys Chem Chem Phys, 2005, 7, 3297-3305) segmented contracted Gaussian basis sets of split, triple-zeta and quadruple-zeta valence quality for the atoms Rb-Rn (except lanthanides). These basis sets are designed for use in connection with small-core effective core potentials including scalar relativistic corrections. Hereby accurate resolution-of-the-identity calculations with second-order M phi ller-Plesset perturbation theory (MP2) and related methods can now be performed for molecules containing elements from H to Rn. The error of the RI approximation has been evaluated for a test set of 385 small and medium sized molecules, which represent the common oxidation states of each element, and is compared with the one-electron basis set error, estimated based on highly accurate explicitly correlated MP2-R12 calculations. With the reported auxiliary basis sets the RI error for MP2 correlation energies is typically two orders of magnitude smaller than the one-electron basis set error, independent on the position of the atoms in the periodic table.