Calculations of solid-state Ca NMR parameters: A comparison of periodic and cluster approaches and an evaluation of DFT functionals.

We present a computational study of magnetic-shielding and quadrupolar-coupling tensors of Ca sites in crystalline solids. A comparison between periodic and cluster-based approaches for modeling solid-state interactions demonstrates that cluster-based approaches are suitable for predicting Ca NMR parameters. Several model chemistries, including Hartree-Fock theory and 17 DFT approximations (SVWN, CA-PZ, PBE, PBE0, PW91, B3PW91, rPBE, PBEsol, WC, PKZB, BMK, M06-L, M06, M06-2X, M06-HF, TPSS, and TPSSh), are evaluated for the prediction of Ca NMR parameters. Convergence of NMR parameters with respect to basis sets of the form cc-pVXZ (X = D, T, Q) is also evaluated. All DFT methods lead to substantial, and frequently systematic, overestimations of experimental chemical shifts. Hartree-Fock calculations outperform all DFT methods for the prediction of Ca chemical-shift tensors. © 2017 Wiley Periodicals, Inc.