<scp>SVECV</scp> ‐f12: Benchmark of a composite scheme for accurate and cost effective evaluation of reaction barriers
Oscar N. Ventura, Martina Kieninger, Aline Katz, Maurício Vega-Teijido, Marc E. Segovia, Kenneth Irving
Abstract
Abstract A simple composite scheme is presented and benchmarked against the 38 reactions in Truhlar's HTBH38/08 and NHTBH38/08 databases. Mean unsigned deviation (MUD) for the complete set of 68 independent barriers is 0.40 kcal mol −1 , compared to 1.31 kcal mol −1 for G4 and 1.62 kcal mol −1 for the M06‐2X‐D3 method. The MUD of the new scheme on the barriers in the DBH24/08 subset (12 out of the 38 reactions in the other sets) is 0.27 kcal mol −1 , better than that obtained at the expensive CCSD(T,full)/aug‐cc‐pCV(T+d)Z level (0.46 kcal mol −1 ) and comparable to the most exact (and costly) Wn calculations (MUD = 0.14 kcal mol −1 ). The method was further tested against a subset of reactions, for which the geometry and energies of all species were determined at the much more demanding CCSD(T)‐F12//pVQZ‐F12 level. The SVECV‐f12 procedure on this database results in RMSE and MUD values of only 0.21 and 0.16 kcal mol −1 .