Spin-orbit effects on the 125Te magnetic-shielding tensor: A cluster-based ZORA/DFT investigation

Fahri Alkan; Cecil Dybowski

doi:10.1016/j.ssnmr.2018.08.005

Spin-orbit effects on the ¹²⁵Te magnetic-shielding tensor: A cluster-based ZORA/DFT investigation

Solid State Nucl Magn Reson. 2018 Nov:95:6-11. doi: 10.1016/j.ssnmr.2018.08.005. Epub 2018 Aug 28.

Authors

Fahri Alkan¹, Cecil Dybowski²

Affiliations

¹ Department of Chemistry, Kansas State University, Manhattan, KS, 66506, USA.
² Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, 19716, USA. Electronic address: dybowski@udel.edu.

PMID: 30189330
DOI: 10.1016/j.ssnmr.2018.08.005

Abstract

Cluster-based calculations of ¹²⁵Te magnetic-shielding tensors demonstrate that inclusion of spin-orbit effects is necessary to obtain the best agreement of theoretical predictions with experiment. The spin-orbit contribution to shielding depends on the oxidation state and stereochemistry of the ¹²⁵Te site. Comparison of the performance of various density functionals indicates that GGA functionals behave similarly to each other in predicting NMR magnetic shielding. The use of hybrid functionals improves the predictive ability on average for a large set of ¹²⁵Te-containing materials. The amount of Hartree-Fock exchange affects the predicted parameters. Inclusion of larger Hartree-Fock exchange contributions in hybrid functionals results in larger slopes of the correlation between calculated magnetic-shielding and experimental chemical-shift principal components, by 10-15% from the ideal value.

Keywords: Calculation; DFT; NMR; Nuclear magnetic resonance; Relativistic Hamiltonian; Tellurium.