Investigating the Effects of Basis Set on Metal鈥揗etal and Metal鈥揕igand Bond Distances in Stable Transition Metal Carbonyls: Performance of Correlation Consistent Basis Sets with 35 Density Functionals

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• 作者：Beulah S. Narendrapurapu ; Nancy A. Richardson ; Andreas V. Copan ; Marissa L. Estep ; Zheyue Yang ; Henry F. Schaefer ; III
• 刊名：Journal of Chemical Theory and Computation
• 出版年：2013
• 出版时间：July 9, 2013
• 年：2013
• 卷：9
• 期：7
• 页码：2930-2938
• 全文大小：261K
• 年卷期：v.9,no.7(July 9, 2013)
• ISSN：1549-9626

文摘

Density functional theory (DFT) is a widely used method for predicting equilibrium geometries of organometallic compounds involving transition metals, with a wide choice of functional and basis set combinations. A study of the role of basis set size in predicting the structural parameters can be insightful with respect to the effectiveness of using small basis sets to optimize larger molecular systems. For many organometallic systems, the metal鈥搈etal and metal鈥揷arbon distances are the most important structural features. In this study, we compare the equilibrium metal鈥搇igand and metal鈥搈etal distances of six transition metal carbonyl compounds predicted by the Hood-Pitzer double-味 polarization (DZP) basis set, against those predicted employing the standard correlation consistent cc-pVXZ (X = D,T,Q) basis sets, for 35 different DFT methods. The effects of systematically increasing the basis set size on the structural parameters are carefully investigated. The Mn鈥揗n bond distance in Mn₂(CO)₁₀ shows a greater dependence on basis set size compared to the other M鈥揗 bonds. However, the DZP predictions for r_e(Mn鈥揗n) are closer to experiment than those obtained with the much larger cc-pVQZ basis set. Our results show that, in general, DZP basis sets predict structural parameters with an accuracy comparable to the triple and quadruple-味 basis sets. This finding is very significant, because the quadruple-味 basis set for Mn₂(CO)₁₀ includes 1308 basis functions, while the equally effective double-味 set (DZP) includes only 366 basis functions. Overall, the DZP M06-L method predicts structures that are very consistent with experiment.