Density Functional Theory based Electric Field Gradient Database

TL;DR

This paper presents a large database of predicted electric field gradients for over 15,000 materials using density functional theory, aiding the search for nuclear quadrupole resonance signals in new materials.

Contribution

It introduces a high-throughput DFT-based EFG database for thousands of materials, with validation against experimental data and publicly accessible tools.

Findings

High accuracy of EFG predictions validated against experiments

Database includes over 15,000 materials with EFG data

Tools available for researchers to access and utilize the data

Abstract

The deviation of the electron density around the nuclei from spherical symmetry determines the electric field gradient (EFG), which can be measured by various types of spectroscopy. Nuclear Quadrupole Resonance (NQR) is particularly sensitive to the EFG. The EFGs, and by implication NQR frequencies, vary dramatically across materials. Consequently, searching for NQR spectral lines in previously uninvestigated materials represents a major challenge. Calculated EFGs can significantly aid at the search inception. To facilitate this task, we have applied high-throughput density functional theory calculations to predict EFGs for 15187 materials in the JARVIS-DFT database. This database, which will include EFG as a standard entry, is continuously increasing. Given the large scope of the database, it is impractical to verify each calculation. However, we assess accuracy by singling out cases for which reliable experimental information is readily available and compare them to the calculations. We further present a statistical analysis of the results. The database and tools associated with our work are made publicly available by JARVIS-DFT ( https://www.ctcms.nist.gov/~knc6/JVASP.html ) and NIST-JARVIS API ( http://jarvis.nist.gov ).