Study of structural, optical, mechanical, thermoelectric, and hydrogen storage properties of CsXH3 (X = Ca, Sr, Ba) hydrides.

Hydrogen storage has garnered significant interest in recent years due to hydrogen's potential as an energy source. Research in this area focuses on exploring the hydrogen storage capabilities of newly identified compounds. This study presents a characterization of CsXH 3 (X = Ca, Sr, Ba) perovskite-type hydride compounds for the first time to assess their potential for hydrogen storage applications. The structural, mechanical, electronic, optical, and thermoelectric responses of studied hydrides are examined utilizing WIEN2k software. The calculated formation energy (ΔH F) values for CsCaH 3 , CsSrH 3, and CsBaH 3 are noticed as −3.20, −2.80, and −2.65 eV, respectively, ensuring their thermodynamic stability of these hydrides. The studied compositions exhibit their direct band gap of 3.21, 2.75, and 2.25 eV, which align well with other theoretical studies. Analysis of optical behavior exhibits that absorption of electromagnetic radiation starts in visible spectra and becomes maximum in the UV range. Furthermore, temperature-dependent transport characteristics including σ, κ e , S, PF, C v, and ZT are evaluated utilizing the BoltzTraP code. The large value of ZT suggests their suitability for thermoelectric application. For CsCaH 3 , CsSrH 3, and CsBaH 3 , the gravimetric ratios for hydrogen storage are 1.75, 1.34, and 1.10 wt %, respectively. This computational analysis marks a significant advancement in understanding different physical properties and possible implications of these hydrides in the fields of thermoelectric and hydrogen storage. [Display omitted] • The perovskites hydrides are emergent materials for hydrogen storage. • Structural, thermodynamic and thermally stable. • Thermodynamic, structural, and mechanical stability. • The absorption bands of light energy exist in the ultraviolet to the visible region. • The Large Debye and melting temperatures make them suitable for industrial applications. [ABSTRACT FROM AUTHOR]