title: Accurate Electron Densities at Nuclei Using Small Ramp-Gaussian Basis Sets.
abstract: 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.
authors.affiliation: Department of Physics and Astronomy, University College London , London WC1E 6BT, United Kingdom.|Research School of Chemistry, Australian National University , Canberra 2601, Australia.
authors.forename: Laura K
authors.initials: LK
authors.lastname: McKemmish
authors.affiliation: Research School of Chemistry, Australian National University , Canberra 2601, Australia.
authors.forename: Andrew T B
authors.initials: AT
authors.lastname: Gilbert