CrMn2Se3 is Caswellsilverite-like structured and crystallizes in the orthorhombic Immm space group. Cr(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form CrSe6 octahedra that share corners with two equivalent Cr(1)Se6 octahedra, corners with four equivalent Mn(1)Se6 octahedra, edges with two equivalent Cr(1)Se6 octahedra, and edges with ten equivalent Mn(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. Mn(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form MnSe6 octahedra that share corners with two equivalent Cr(1)Se6 octahedra, corners with four equivalent Mn(1)Se6 octahedra, edges with five equivalent Cr(1)Se6 octahedra, and edges with seven equivalent Mn(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Cr(1) and four equivalent Mn(1) atoms to form a mixture of corner and edge-sharing SeMn4Cr2 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Se site, Se(2) is bonded to two equivalent Cr(1) and four equivalent Mn(1) atoms to form a mixture of corner and edge-sharing SeMn4Cr2 octahedra. The corner-sharing octahedral tilt angles range from 0-1°.
CrMn2Se3 is Caswellsilverite-like structured and crystallizes in the orthorhombic Immm space group. Cr(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form CrSe6 octahedra that share corners with two equivalent Cr(1)Se6 octahedra, corners with four equivalent Mn(1)Se6 octahedra, edges with two equivalent Cr(1)Se6 octahedra, and edges with ten equivalent Mn(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. Both Cr(1)-Se(2) bond lengths are 2.71 Å. All Cr(1)-Se(1) bond lengths are 2.64 Å. Mn(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form MnSe6 octahedra that share corners with two equivalent Cr(1)Se6 octahedra, corners with four equivalent Mn(1)Se6 octahedra, edges with five equivalent Cr(1)Se6 octahedra, and edges with seven equivalent Mn(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. Both Mn(1)-Se(2) bond lengths are 2.68 Å. All Mn(1)-Se(1) bond lengths are 2.71 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Cr(1) and four equivalent Mn(1) atoms to form a mixture of corner and edge-sharing SeMn4Cr2 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Se site, Se(2) is bonded to two equivalent Cr(1) and four equivalent Mn(1) atoms to form a mixture of corner and edge-sharing SeMn4Cr2 octahedra. The corner-sharing octahedral tilt angles range from 0-1°.