Mn4NiSe5 crystallizes in the orthorhombic Immm space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 6-coordinate geometry to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms. In the second Mn site, Mn(2) is bonded in a 4-coordinate geometry to two equivalent Se(1) and four equivalent Se(2) atoms. Ni(1) is bonded to two equivalent Se(3) and four equivalent Se(1) atoms to form a mixture of corner and edge-sharing NiSe6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Mn(1), two equivalent Mn(2), and two equivalent Ni(1) atoms to form a mixture of corner and edge-sharing SeMn4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-36°. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent Mn(1) and four equivalent Mn(2) atoms. In the third Se site, Se(3) is bonded to four equivalent Mn(1) and two equivalent Ni(1) atoms to form a mixture of distorted corner and edge-sharing SeMn4Ni2 octahedra. The corner-sharing octahedra are not tilted.
Mn4NiSe5 crystallizes in the orthorhombic Immm space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 6-coordinate geometry to two equivalent Se(1), two equivalent Se(2), and two equivalent Se(3) atoms. Both Mn(1)-Se(1) bond lengths are 2.48 Å. Both Mn(1)-Se(2) bond lengths are 2.39 Å. Both Mn(1)-Se(3) bond lengths are 3.04 Å. In the second Mn site, Mn(2) is bonded in a 4-coordinate geometry to two equivalent Se(1) and four equivalent Se(2) atoms. Both Mn(2)-Se(1) bond lengths are 2.49 Å. There are two shorter (2.44 Å) and two longer (3.21 Å) Mn(2)-Se(2) bond lengths. Ni(1) is bonded to two equivalent Se(3) and four equivalent Se(1) atoms to form a mixture of corner and edge-sharing NiSe6 octahedra. The corner-sharing octahedra are not tilted. Both Ni(1)-Se(3) bond lengths are 2.36 Å. All Ni(1)-Se(1) bond lengths are 2.45 Å. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Mn(1), two equivalent Mn(2), and two equivalent Ni(1) atoms to form a mixture of corner and edge-sharing SeMn4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-36°. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent Mn(1) and four equivalent Mn(2) atoms. In the third Se site, Se(3) is bonded to four equivalent Mn(1) and two equivalent Ni(1) atoms to form a mixture of distorted corner and edge-sharing SeMn4Ni2 octahedra. The corner-sharing octahedra are not tilted.