Exploring superconducting signatures in high-pressure hydride compounds: An electronic-structure analysis

Employing density functional theory, we investigated the band structure dispersion and density of states (DOS) of hydrogen clathrate materials AH₁₀ (where A=Sc, Y, Lu, Ce, Ac, Th, and Lr). These compounds were compared to the synthesized LaH₁₀ superconductor. A comparative model was utilized to extract predictive parameters as a fingerprint of superconductivity for probable $fcc$-hydrides. The band structure of LaH₁₀ was examined under high pressure, focusing on energy gap variations at specific Brillouin zone points, new parameters derived from band structure data at these points were suggested: $\Delta E_{\Gamma },\Delta E_K$ and $\Delta E_Z$. Additionally, two other parameters derived from DOS were proposed: the elemental contribution to the total DOS (N(E_F) in percentage) and the energetic shift of the van Hove singularity peak in the total DOS ($\Delta E_{\text{vHs}}$). Correlations between these parameters and the $Fm\overline{3}m$ material's stability and superconducting properties were explored. YH₁₀, AcH₁₀, and ScH₁₀ (hypothetically stable in the $Fm\overline{3}m$ structure) exhibited trends similar to LaH₁₀. Conversely, LrH₁₀ displayed a distinct trend, suggesting a potential increase in critical temperature at pressures exceeding 300 GPa. Based on this study, AcH₁₀ and LrH₁₀ were identified as the compounds most closely resembling LaH₁₀ and YH₁₀. However, AcH₁₀ may require extremely high pressures (above 350 GPa) to stabilize in the $Fm\overline{3}m$ structure.