skip to main content

SciTech ConnectSciTech Connect

Title: An efficient extrapolation to the (T)/CBS limit

We extrapolate to the perturbative triples (T)/complete basis set (CBS) limit using double ζ basis sets without polarization functions (Wesleyan-1-Triples-2ζ or “Wes1T-2Z”) and triple ζ basis sets with a single level of polarization functions (Wesleyan-1-Triples-3ζ or “Wes1T-3Z”). These basis sets were optimized for 102 species representing the first two rows of the Periodic Table. The species include the entire set of neutral atoms, positive and negative atomic ions, as well as several homonuclear diatomic molecules, hydrides, rare gas dimers, polar molecules, such as oxides and fluorides, and a few transition states. The extrapolated Wes1T-(2,3)Z triples energies agree with (T)/CBS benchmarks to within ±0.65 mE{sub h}, while the rms deviations of comparable model chemistries W1, CBS-APNO, and CBS-QB3 for the same test set are ±0.23 mE{sub h}, ±2.37 mE{sub h}, and ±5.80 mE{sub h}, respectively. The Wes1T-(2,3)Z triples calculation time for the largest hydrocarbon in the G2/97 test set, C{sub 6}H{sub 5}Me{sup +}, is reduced by a factor of 25 when compared to W1. The cost-effectiveness of the Wes1T-(2,3)Z extrapolation validates the usefulness of the Wes1T-2Z and Wes1T-3Z basis sets which are now available for a more efficient extrapolation of the (T) component of any composite model chemistry.
Authors:
 [1] ;  [2]
  1. Hall-Atwater Laboratories of Chemistry, Wesleyan University, Middletown, Connecticut 06459-0180 (United States)
  2. Department of Chemistry, Southern Connecticut State University, 501 Crescent Street, New Haven, Connecticut 06515-1355 (United States)
Publication Date:
OSTI Identifier:
22252825
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 140; Journal Issue: 18; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; COMPOSITE MODELS; EXTRAPOLATION; FLUORIDES; HYDROCARBONS; OXIDES; POLARIZATION