Correlation consistent basis sets for molecular core-valence effects with explicitly correlated wave functions: The atoms B-Ne and Al-Ar
Correlation consistent basis sets for molecular core-valence effects with explicitly correlated wave functions: The atoms B-Ne and Al-Ar
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DOI：
10.1063/1.3308483
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发表时间：
2010-02-07
影响因子：
4.4
通讯作者：
Peterson, Kirk A.
中科院分区：
文献类型：
--
作者：
Hill, J. Grant;Mazumder, Shivnath;Peterson, Kirk A.
相关性一致性基组已经过优化，可通过显式相关的 F12 方法准确描述核-核和核-价相关效应。新组表示为 cc-pCVnZ-F12 (n=D, T, Q) 和 aug-cc-pC(F12)VnZ (n=D, T, Q, 5)，是通过使用附加函数增强 cc-pVnZ-F12 和 aug-cc-pVnZ 基组系列而开发的，这些函数的指数根据全电子和价电子相关性之间的差异进行了优化能量。一般来说，添加的增强函数数量少于标准 cc-pCVnZ 和 cc-pwCVnZ 基组系列。给出了在 MP2-F12 计算中与这些基组一起使用的双子 Slater 指数的最佳值，并且还建议用于 CCSD-F12b 计算。用于解析显式相关计算中的恒等近似的辅助基组也已优化并与新的 cc-pCVnZ-F12 系列轨道基组相匹配。 cc-pCVnZ-F12 基组以及新的辅助组在 CCSD(T)-F12b 计算一系列同核和异核第一和第二行双原子分子的光谱特性中进行了基准测试。将这些分子中的外核电子与在完整基组极限下的传统 CCSD(T) 的相关效果进行比较，其中涉及使用新的 cc-pCV6Z 基组对第二行元素进行计算，这也是在本工作过程中开发的，观察到 F12 值在三 zeta 能级上已经相当好地收敛。 (c) 2010 年美国物理研究所。 [doi:10.1063/1.3308483]
Correlation consistent basis sets have been optimized for accurately describing core-core and core-valence correlation effects with explicitly correlated F12 methods. The new sets, denoted cc-pCVnZ-F12 (n=D, T, Q) and aug-cc-pC(F12)VnZ (n=D, T, Q, 5), were developed by augmenting the cc-pVnZ-F12 and aug-cc-pVnZ families of basis sets with additional functions whose exponents were optimized based on the difference between all-electron and valence-electron correlation energies. The number of augmented functions added is fewer, in general, than in the standard cc-pCVnZ and cc-pwCVnZ families of basis sets. Optimal values of the geminal Slater exponent for use with these basis sets in MP2-F12 calculations are presented and are also recommended for CCSD-F12b calculations. Auxiliary basis sets for use in the resolution of the identity approximation in explicitly correlated calculations have also been optimized and matched to the new cc-pCVnZ-F12 series of orbital basis sets. The cc-pCVnZ-F12 basis sets, along with the new auxiliary sets, were benchmarked in CCSD(T)-F12b calculations of spectroscopic properties on a series of homo- and heteronuclear first and second row diatomic molecules. Comparing the effects of correlating the outer core electrons in these molecules with those from conventional CCSD(T) at the complete basis set limit, which involved calculations with new cc-pCV6Z basis sets for the second row elements that were also developed in the course of this work, it is observed that the F12 values are reasonably well converged already at just the triple-zeta level. (c) 2010 American Institute of Physics. [doi:10.1063/1.3308483]