Evaluation of the Factors Impacting the Accuracy of 13C NMR Chemical Shift Predictions using Density Functional Theory-The Advantage of Long-Range Corrected Functionals

Mark A Iron

doi:10.1021/acs.jctc.7b00772

Evaluation of the Factors Impacting the Accuracy of ¹³C NMR Chemical Shift Predictions using Density Functional Theory-The Advantage of Long-Range Corrected Functionals

J Chem Theory Comput. 2017 Nov 14;13(11):5798-5819. doi: 10.1021/acs.jctc.7b00772. Epub 2017 Nov 2.

Author

Mark A Iron¹

Affiliation

¹ Computational Chemistry Unit, Department of Chemical Research Support, Weizmann Institute of Science , Rehovot 7610001, Israel.

PMID: 29016125
DOI: 10.1021/acs.jctc.7b00772

Abstract

The various factors influencing the accuracy of ¹³C NMR calculations using density functional theory (DFT), including the basis set, exchange-correlation (XC) functional, and isotropic shielding calculation method, are evaluated. A wide selection of XC functionals (over 70) were considered, and it was found that long-range corrected functionals offer a significant improvement over the other classes of functionals. Based on a thorough study, it is recommended that for calculating NMR chemical shifts (δ) one should use the CSGT method, the COSMO solvation model, and the LC-TPSSTPSS exchange-correlation functional in conjunction with the cc-pVTZ basis set. A selection of problems in natural product identification are considered in light of the newly recommended level of theory.