## Metal hydrides under high pressure

We exhaustively search quaternary metal hydrides based on the (13-2-1) and (13-3-1) structures that are the two of the putative densest ternary sphere packings in cubic systems [R. Koshoji et al., Phys. Rev. E 104, 024101 (2021)]. The 73304 candidate hydrides are generated by substituting the small spheres with hydrogen atoms, the medium, large, and fourth spheres with metallic atoms. Especially, the substitution of the small spheres with hydrogen atoms gives the unconventional hydrogen sublattices. We screen unstable hydrides in the candidates through geometrical optimizations, constant pressure molecular dynamics simulations, and phonon calculations under hydrostatic pressure of 10 GPa, and identify 23 hydrides with static and dynamic stability.
In this page, there are three links to give the structural data of hydrides that show the dynamic stability in the first screening: Geometrical optimization and molecular dynamics simulations in the $1 \times 1 \times 1$ unit cell. We expect that the 357 hydrides screened from 73304 hydrides provide a guideline to narrow down the search space for trials in the experimental synthesis of quaternary metal hydrides.