High-pressure study of ScH3: Raman, infrared, and visible absorption spectroscopy

with a hexagonal structure, in which the Ylattice crystallizes into the hcp structure and accommodates Hatoms into tetrahedron (T) and octahedron (O) sites. The Hatoms in the O site are known to be positioned not at the centerof the octahedron but near the metal basal planes. For La withan ionic radius larger than that of Y, a structural transition doesnot occur, but a metal-insulator transition does occur duringhydrogenation from LaH