Effect of dynamical motion in ab initio studies of magnetic resonance spectroscopy*

We study 14N, 23Na, and 17O nuclear quadrupole resonance (NQR) and solid-state nuclear magnetic resonance (SSNMR) spectroscopy by calculating electric field gradient (EFG) parameters in ferroelectric NaNO2. In addition to static EFG calculations, we developed a new method to analyze how the dynamics of atoms influence EFGs. To this end, we used first-principles density functional theory (DFT) based molecular dynamics (MD) with projector augmented wave (PAW) potentials to simulate the dynamics of atoms. We then calculate EFG parameters from uncorrelated snapshots of different geometrical configurations. We show the extent to which the EFG parameters in static DFT calculations can be corrected under such dynamical considerations. Moreover, this study provides fundamental insights into how the variation in EFGs is related to atomic motions. We believe this work will serve as a reliable fundamental step towards exploring NQR/SSNMR of more complicated quantum systems.