Rh3Se is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are three inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to eight Rh(1,1) and four equivalent Se(1) atoms to form distorted RhRh8Se4 cuboctahedra that share corners with four equivalent Se(1)Rh12 cuboctahedra; corners with fourteen Rh(1,1)Rh8Se4 cuboctahedra; edges with six equivalent Se(1)Rh12 cuboctahedra; edges with twelve Rh(1,1)Rh8Se4 cuboctahedra; faces with four equivalent Se(1)Rh12 cuboctahedra; and faces with sixteen Rh(1,1,1)Rh8Se4 cuboctahedra. In the second Rh site, Rh(1) is bonded to eight Rh(1,1) and four equivalent Se(1) atoms to form distorted RhRh8Se4 cuboctahedra that share corners with four equivalent Se(1)Rh12 cuboctahedra; corners with fourteen Rh(1,1)Rh8Se4 cuboctahedra; edges with six equivalent Se(1)Rh12 cuboctahedra; edges with twelve Rh(1,1)Rh8Se4 cuboctahedra; faces with four equivalent Se(1)Rh12 cuboctahedra; and faces with sixteen Rh(1,1,1)Rh8Se4 cuboctahedra. In the third Rh site, Rh(1) is bonded to eight Rh(1,1) and four equivalent Se(1) atoms to form distorted RhRh8Se4 cuboctahedra that share corners with four equivalent Se(1)Rh12 cuboctahedra; corners with fourteen Rh(1,1,1)Rh8Se4 cuboctahedra; edges with six equivalent Se(1)Rh12 cuboctahedra; edges with twelve Rh(1,1)Rh8Se4 cuboctahedra; faces with four equivalent Se(1)Rh12 cuboctahedra; and faces with sixteen Rh(1,1,1)Rh8Se4 cuboctahedra. Se(1) is bonded to twelve Rh(1,1,1) atoms to form SeRh12 cuboctahedra that share corners with six equivalent Se(1)Rh12 cuboctahedra; corners with twelve Rh(1,1,1)Rh8Se4 cuboctahedra; edges with eighteen Rh(1,1,1)Rh8Se4 cuboctahedra; faces with eight equivalent Se(1)Rh12 cuboctahedra; and faces with twelve Rh(1,1,1)Rh8Se4 cuboctahedra.
Rh3Se is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are three inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to eight Rh(1,1) and four equivalent Se(1) atoms to form distorted RhRh8Se4 cuboctahedra that share corners with four equivalent Se(1)Rh12 cuboctahedra; corners with fourteen Rh(1,1)Rh8Se4 cuboctahedra; edges with six equivalent Se(1)Rh12 cuboctahedra; edges with twelve Rh(1,1)Rh8Se4 cuboctahedra; faces with four equivalent Se(1)Rh12 cuboctahedra; and faces with sixteen Rh(1,1,1)Rh8Se4 cuboctahedra. There are a spread of Rh(1)-Rh(1,1) bond distances ranging from 2.74-2.83 Å. There are two shorter (2.76 Å) and two longer (2.80 Å) Rh(1)-Se(1) bond lengths. In the second Rh site, Rh(1) is bonded to eight Rh(1,1) and four equivalent Se(1) atoms to form distorted RhRh8Se4 cuboctahedra that share corners with four equivalent Se(1)Rh12 cuboctahedra; corners with fourteen Rh(1,1)Rh8Se4 cuboctahedra; edges with six equivalent Se(1)Rh12 cuboctahedra; edges with twelve Rh(1,1)Rh8Se4 cuboctahedra; faces with four equivalent Se(1)Rh12 cuboctahedra; and faces with sixteen Rh(1,1,1)Rh8Se4 cuboctahedra. There are a spread of Rh(1)-Rh(1) bond distances ranging from 2.74-2.83 Å. There are two shorter (2.76 Å) and two longer (2.80 Å) Rh(1)-Se(1) bond lengths. In the third Rh site, Rh(1) is bonded to eight Rh(1,1) and four equivalent Se(1) atoms to form distorted RhRh8Se4 cuboctahedra that share corners with four equivalent Se(1)Rh12 cuboctahedra; corners with fourteen Rh(1,1,1)Rh8Se4 cuboctahedra; edges with six equivalent Se(1)Rh12 cuboctahedra; edges with twelve Rh(1,1)Rh8Se4 cuboctahedra; faces with four equivalent Se(1)Rh12 cuboctahedra; and faces with sixteen Rh(1,1,1)Rh8Se4 cuboctahedra. There are a spread of Rh(1)-Rh(1) bond distances ranging from 2.74-2.83 Å. There are two shorter (2.76 Å) and two longer (2.80 Å) Rh(1)-Se(1) bond lengths. Se(1) is bonded to twelve Rh(1,1,1) atoms to form SeRh12 cuboctahedra that share corners with six equivalent Se(1)Rh12 cuboctahedra; corners with twelve Rh(1,1,1)Rh8Se4 cuboctahedra; edges with eighteen Rh(1,1,1)Rh8Se4 cuboctahedra; faces with eight equivalent Se(1)Rh12 cuboctahedra; and faces with twelve Rh(1,1,1)Rh8Se4 cuboctahedra.