McKemmish Laura K, Gilbert Andrew T B
Department of Physics and Astronomy, University College London , London WC1E 6BT, United Kingdom.
Research School of Chemistry, Australian National University , Canberra 2601, Australia.
J Chem Theory Comput. 2015 Aug 11;11(8):3679-83. doi: 10.1021/acs.jctc.5b00528.
Electron densities at nuclei are difficult to calculate accurately with all-Gaussian basis sets because they lack an electron-nuclear cusp. The newly developed mixed ramp-Gaussian basis sets, such as R-31G, possess electron-nuclear cusps due to the presence of ramp functions in the basis. The R-31G basis set is a general-purpose mixed ramp-Gaussian basis set modeled on the 6-31G basis set. The prediction of electron densities at nuclei using R-31G basis sets for Li-F outperforms Dunning, Pople, and Jensen general purpose all-Gaussian basis sets of triple-ζ quality or lower and the cc-pVQZ basis set. It is of similar quality to the specialized pcJ-0 basis set which was developed with partial decontraction of core functions and extra high exponent s-Gaussians to predict electron density at the nucleus. These results show significant advantages in the properties of mixed ramp-Gaussian basis sets compared to all-Gaussian basis sets.
对于全高斯基组而言，原子核处的电子密度很难精确计算，因为它们缺少电子-核尖点。新开发的混合斜坡-高斯基组，如R-31G，由于基中存在斜坡函数而具有电子-核尖点。R-31G基组是一个通用的混合斜坡-高斯基组，以6-31G基组为模型。使用R-31G基组对Li-F原子核处电子密度的预测优于邓宁、波普尔和詹森的三重ζ质量或更低的通用全高斯基组以及cc-pVQZ基组。它与专门开发的pcJ-0基组质量相似，pcJ-0基组通过对核心函数进行部分去收缩和使用超高指数s-高斯函数来预测原子核处的电子密度。这些结果表明，与全高斯基组相比，混合斜坡-高斯基组在性质上具有显著优势。
