DOE OSTI2020
Rh3Se is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Rh sites. In the first Rh site, Rh is bonded to eight Rh and four equivalent Se atoms to form distorted RhRh8Se4 cuboctahedra that share corners with four equivalent SeRh12 cuboctahedra, corners with fourteen RhRh8Se4 cuboctahedra, edges with six equivalent SeRh12 cuboctahedra, edges with twelve RhRh8Se4 cuboctahedra, faces with four equivalent SeRh12 cuboctahedra, and faces with sixteen RhRh8Se4 cuboctahedra. There are a spread of Rh–Rh bond distances ranging from 2.74–2.83 Å. There are two shorter (2.76 Å) and two longer (2.80 Å) Rh–Se bond lengths. In the second Rh site, Rh is bonded to eight equivalent Rh and four equivalent Se atoms to form distorted RhRh8Se4 cuboctahedra that share corners with four equivalent SeRh12 cuboctahedra, corners with fourteen RhRh8Se4 cuboctahedra, edges with six equivalent SeRh12 cuboctahedra, edges with twelve equivalent RhRh8Se4 cuboctahedra, faces with four equivalent SeRh12 cuboctahedra, and faces with sixteen RhRh8Se4 cuboctahedra. There are two shorter (2.76 Å) and two longer (2.80 Å) Rh–Se bond lengths. Se is bonded to twelve Rh atoms to form SeRh12 cuboctahedra that share corners with six equivalent SeRh12 cuboctahedra, corners with twelve equivalent RhRh8Se4 cuboctahedra, edges with eighteen RhRh8Se4 cuboctahedra, faces with eight equivalent SeRh12 cuboctahedra, and faces with twelve RhRh8Se4 cuboctahedra.