Spin Orbit Coupling for Superconductivity Models of LaH ₁₀

ABSTRACT Systematic evaluation of spin orbit coupling on models for cubic LaH 10 (SG: ) at pressure is based on ab initio density functional theory calculations with optimized experimental cell dimensions. Primitive lattice LaH 10 band structure details show asymmetric cosine‐shaped bands that link key lattice nodes and cross the Fermi level. Crystal orbital overlap populations show that H─H bonds in the cubic unit cell contribute to bonding–antibonding transitions evident in cosine‐shaped bands along the Γ–X reciprocal direction. Measures of energy asymmetry for these cosine‐shaped bands reveal matches of calculated T c with experimental T c values for cubic LaH 10 at pressures between 135 and ∼220 GPa. Electron density distributions associated with asymmetry of the LaH 10 irregular chamfered cube are attributed to variations in hydrogen bonding with pressure. Changes to lattice vibrations between 135 and 220 GPa are co‐incident with experimental and theoretical evidence for structural transformations at these pressures. Collective behaviour of hydrogen lattice vibrations and asymmetric changes to crystal structure are consistent with the dome‐like format for experimental T c values with pressure.