DFT-based study of NaYH3 and NaWH3 perovskite hydrides: Structural, mechanical, electronic, and optical insights for hydrogen storage

Abstract

Hydrogen is increasingly recognized as a vital component in the transition toward sustainable energy, owing to its abundance and environmentally friendly lifecycle. Solid-state hydrogen storage is attracting interest due to fast kinetics, favorable gravimetric, volumetric capacities, and good reversibility. In his study, we explore the hydrogen storage potential of two novel perovskite hydrides, NaYH 3 and NaWH 3 , using density functional theory (DFT) calculations performed with the CASTEP code. We investigated the structural, mechanical, electronic, and optical properties of these compounds. Both hydrides exhibit negative formation energies, confirming their thermodynamic stability. The hydrogen storage capacities were estimated to be 3.64 wt% and 1.42 wt% for NaYH 3 and NaWH 3 , respectively. Elastic constants meet the mechanical stability criteria, and NaYH 3 shows greater ductility, as indicated by its (Poisson’s ratio, B/G ratio). Electronic density of states analysis confirms metallic behavior. Optical analysis shows that NaYH 3 offers enhanced dielectric performance and absorption. Overall, both compounds, particularly NaYH 3 , emerge as promising candidates for efficient solid-state hydrogen storage applications.