xOPBE: A Specialized Functional for Accurate Prediction of 13C Chemical Shifts

Jinkun Zhang; Qing Ye; Chao Yin; Anan Wu; Xin Xu

doi:10.1021/acs.jpca.0c02873

xOPBE: A Specialized Functional for Accurate Prediction of ¹³C Chemical Shifts

J Phys Chem A. 2020 Jul 16;124(28):5824-5831. doi: 10.1021/acs.jpca.0c02873. Epub 2020 Jul 7.

Authors

Jinkun Zhang¹, Qing Ye¹, Chao Yin¹, Anan Wu¹, Xin Xu²

Affiliations

¹ Department of Chemistry, College of Chemistry and Chemical Engineering, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen University, Xiamen 361005, China.
² Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai 200438, China.

PMID: 32579357
DOI: 10.1021/acs.jpca.0c02873

Abstract

In this study, we present a new hybrid functional denoted as xOPBE, which is optimized at the 6-311+G(2d,p) basis set and designed with a specific aim of providing accurate ¹³C chemical shifts. By mixing the Hartree-Fock exchange into the OPBE functional, xOPBE provides a significantly improved overall performance as compared to its parent OPBE functional, while OPBE was shown previously as an excellent functional for ¹³C chemical shifts. Even in the case of the 1-adamantyl cation, for which OPBE completely fails in reproducing the experimental results, xOPBE still performs very well with similar accuracy as the standard CCSD(T) method with a large basis set. Our results also demonstrate that xOPBE not only can improve quantitatively the description of the correct assignments given by OPBE but also can revert OPBE's incorrect assignments qualitatively. Thus, we would like to recommend the use of xOPBE for routine evaluations of ¹³C chemical shifts.