Ni(RhSe2)2 crystallizes in the monoclinic C2/m space group. Rh(1) is bonded in a 7-coordinate geometry to one Ni(1), three equivalent Se(1), and three equivalent Se(2) atoms. Ni(1) is bonded to two equivalent Rh(1), two equivalent Se(2), and four equivalent Se(1) atoms to form distorted edge-sharing NiRh2Se6 octahedra. There are two inequivalent Se sites. In the first Se site, Se(2) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Rh(1) and one Ni(1) atom. In the second Se site, Se(1) is bonded in a 5-coordinate geometry to three equivalent Rh(1) and two equivalent Ni(1) atoms.
Ni(RhSe2)2 crystallizes in the monoclinic C2/m space group. Rh(1) is bonded in a 7-coordinate geometry to one Ni(1), three equivalent Se(1), and three equivalent Se(2) atoms. The Rh(1)-Ni(1) bond length is 2.84 Å. There is one shorter (2.56 Å) and two longer (2.61 Å) Rh(1)-Se(1) bond lengths. There are two shorter (2.48 Å) and one longer (2.52 Å) Rh(1)-Se(2) bond length. Ni(1) is bonded to two equivalent Rh(1), two equivalent Se(2), and four equivalent Se(1) atoms to form distorted edge-sharing NiRh2Se6 octahedra. Both Ni(1)-Se(2) bond lengths are 2.50 Å. All Ni(1)-Se(1) bond lengths are 2.52 Å. There are two inequivalent Se sites. In the first Se site, Se(2) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Rh(1) and one Ni(1) atom. In the second Se site, Se(1) is bonded in a 5-coordinate geometry to three equivalent Rh(1) and two equivalent Ni(1) atoms.