New perspectives in the PAW/GIPAW approach: J(P-O-Si) coupling constants, antisymmetric parts of shift tensors and NQR predictions

In 2001, Pickard and Mauri implemented the gauge including projected augmented wave (GIPAW) protocol for first-principles calculations of NMR parameters using periodic boundary conditions (chemical shift anisotropy and electric field gradient tensors). In this paper, three potentially interesting perspectives in connection with PAW/GIPAW in solid-state NMR and pure nuclear quadrupole resonance (NQR) are presented: (i) the calculation of J coupling tensors in inorganic solids; (ii) the calculation of the antisymmetric part of chemical shift tensors and (iii) the prediction of N-14 and Cl-35 pure NQR resonances including dynamics. We believe that these topics should open new insights in the combination of GIPAW, NMR/NQR crystallography, temperature effects and dynamics. Points (i), (ii) and (iii) will be illustrated by selected examples: (i) chemical shift tensors and heteronuclear 2J(P-O-Si) coupling constants in the case of silicophosphates and calcium phosphates [Si5O(PO4)(6), SiP2O7 polymorphs and alpha-Ca(PO3)(2)]; (ii) antisymmetric chemical shift tensors in cyclopropene derivatives, C3X4 (X = H, Cl, F) and (iii) N-14 and Cl-35 NQR predictions in the case of RDX (C3H6N6O6), beta-HMX (C4H8N8O8), alpha-NTO (C2H2N4O3) and AlOPCl6. RDX, beta-HMX and alpha-NTO are explosive compounds. Copyright (C) 2010 John Wiley & Sons, Ltd