Evaluating Cost and Accuracy in Two-Point Complete Basis Set Extrapolation Schemes Using Efficient Diffuse Basis Sets

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2024-12, Vol.128 (49), p.10673-10679
• Main Authors: Parameswaran, Aiswarya M., Fernández-Ramos, Antonio, Truhlar, Donald G.
• Format: Article
• Language: English
• Subjects: A: New Tools and Methods in Experiment and Theory
• ISSN: 1089-5639; 1520-5215; 1520-5215
• DOI: 10.1021/acs.jpca.4c04710

A widely used procedure for obtaining the complete basis set (CBS) limit of an electronic structure method is to extrapolate results from a sequence of correlation-consistent basis sets. A recent study by Xi et al. [J. Phys. Chem. A 2024, 128, 3742−3749] trained two-point extrapolation schemes against a new extensive dataset using aug-cc-pVXZ (X = D, T, Q, 5, and 6) basis set pairs. Their results were very promising, providing a significant improvement over previous two-point extrapolation schemes. The present work shows that equally good results can be obtained at lower cost by using the smaller jun-cc-pVXZ or jul-cc-pVXZ basis sets, which contain fewer diffuse functions. Using the smaller jun and jul basis sets to extrapolate to the CBS limit provides a good compromise between accuracy and computational cost.