Display options
Cite
Chan B, Radom L. W1X-1 and W1X-2: W1-Quality Accuracy with an Order of Magnitude Reduction in Computational Cost. J Chem Theory Comput. 2012;8(11):4259-69doi: 10.1021/ct300632p.
Chan, B., & Radom, L. (2012). W1X-1 and W1X-2: W1-Quality Accuracy with an Order of Magnitude Reduction in Computational Cost. Journal of chemical theory and computation, 8(11), 4259-69. https://doi.org/10.1021/ct300632p
Chan, Bun, and Radom, Leo. "W1X-1 and W1X-2: W1-Quality Accuracy with an Order of Magnitude Reduction in Computational Cost." Journal of chemical theory and computation vol. 8,11 (2012): 4259-69. doi: https://doi.org/10.1021/ct300632p
Chan B, Radom L. W1X-1 and W1X-2: W1-Quality Accuracy with an Order of Magnitude Reduction in Computational Cost. J Chem Theory Comput. 2012 Nov 13;8(11):4259-69. doi: 10.1021/ct300632p. Epub 2012 Sep 19. PMID: 26605589.
Copy Download .nbib Format: NLM
Share it on

J Chem Theory Comput. 2012 Nov 13;8(11):4259-69. doi: 10.1021/ct300632p. Epub 2012 Sep 19.

W1X-1 and W1X-2: W1-Quality Accuracy with an Order of Magnitude Reduction in Computational Cost.

Journal of chemical theory and computation

Bun Chan, Leo Radom

Affiliations

  1. School of Chemistry and ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia.

PMID: 26605589 DOI: 10.1021/ct300632p

Abstract

We have examined a number of approaches for reducing the computational requirements of the W1w and W1-F12 procedures, while maintaining the accuracy. A key finding is that MP2/cc-pCVTZ provides a reliable means for the evaluation of core-correlation effects at a cost that is negligible in the context of W1-type procedures. This greatly reduces the overall computational cost, since calculations for core-correlation represent the most time-consuming steps for both W1w and W1-F12. For the evaluation of valence CCSD(T)/CBS, we find that truncation of the sets of diffuse functions leads to a significant savings in time, with only a minor deterioration in the performance. In order to eliminate the need to carry out CCSD calculations with a quadruple-ζ basis set, we have maintained the approach employed in W1-F12, namely the use of explicitly correlated procedures. Our resulting procedures are termed W1X-1 and W1X-2 (where the X refers to the eXplicitly correlated procedures). Of these, the W1X-1 protocol requires two CCSD-F12b plus two CCSD(T) calculations to obtain the valence CCSD(T)/CBS energy component, as with W1-F12. The W1X-2 procedure, on the other hand, requires only two CCSD(T)-F12b calculations for the evaluation of CCSD(T)/CBS and is therefore less expensive than W1X-1. Indeed, the W1X-2 protocol is an order of magnitude less computationally demanding than W1w and ∼80% less costly than W1-F12. Extensive assessment of the W1X-1 and W1X-2 procedures shows that W1X-1 performs well and comparably to W1w and W1-F12 in virtually all cases. The W1X-2 method gives equivalently good results for most thermochemical properties, but the heats of formation of fluorocarbons and complexation energies of hydrogen fluoride clusters represent notable exceptions.

Publication Types