MnBiSe2I crystallizes in the monoclinic C2/m space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form MnSe6 octahedra that share corners with two equivalent Mn(2)Se2I4 octahedra, corners with four equivalent Bi(1)Se5 square pyramids, edges with two equivalent Mn(1)Se6 octahedra, and edges with six equivalent Bi(1)Se5 square pyramids. The corner-sharing octahedral tilt angles are 41°. In the second Mn site, Mn(2) is bonded to two equivalent Se(1) and four equivalent I(1) atoms to form MnSe2I4 octahedra that share corners with two equivalent Mn(1)Se6 octahedra, corners with four equivalent Bi(1)Se5 square pyramids, and edges with two equivalent Mn(2)Se2I4 octahedra. The corner-sharing octahedral tilt angles are 41°. Bi(1) is bonded to two equivalent Se(1) and three equivalent Se(2) atoms to form BiSe5 square pyramids that share corners with two equivalent Mn(2)Se2I4 octahedra, corners with two equivalent Mn(1)Se6 octahedra, edges with three equivalent Mn(1)Se6 octahedra, and edges with four equivalent Bi(1)Se5 square pyramids. The corner-sharing octahedral tilt angles range from 13-67°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a rectangular see-saw-like geometry to one Mn(1), one Mn(2), and two equivalent Bi(1) atoms. In the second Se site, Se(2) is bonded to two equivalent Mn(1) and three equivalent Bi(1) atoms to form a mixture of edge and corner-sharing SeMn2Bi3 square pyramids. I(1) is bonded in an L-shaped geometry to two equivalent Mn(2) atoms.
MnBiSe2I crystallizes in the monoclinic C2/m space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form MnSe6 octahedra that share corners with two equivalent Mn(2)Se2I4 octahedra, corners with four equivalent Bi(1)Se5 square pyramids, edges with two equivalent Mn(1)Se6 octahedra, and edges with six equivalent Bi(1)Se5 square pyramids. The corner-sharing octahedral tilt angles are 41°. Both Mn(1)-Se(1) bond lengths are 2.68 Å. All Mn(1)-Se(2) bond lengths are 2.80 Å. In the second Mn site, Mn(2) is bonded to two equivalent Se(1) and four equivalent I(1) atoms to form MnSe2I4 octahedra that share corners with two equivalent Mn(1)Se6 octahedra, corners with four equivalent Bi(1)Se5 square pyramids, and edges with two equivalent Mn(2)Se2I4 octahedra. The corner-sharing octahedral tilt angles are 41°. Both Mn(2)-Se(1) bond lengths are 2.75 Å. All Mn(2)-I(1) bond lengths are 2.86 Å. Bi(1) is bonded to two equivalent Se(1) and three equivalent Se(2) atoms to form BiSe5 square pyramids that share corners with two equivalent Mn(2)Se2I4 octahedra, corners with two equivalent Mn(1)Se6 octahedra, edges with three equivalent Mn(1)Se6 octahedra, and edges with four equivalent Bi(1)Se5 square pyramids. The corner-sharing octahedral tilt angles range from 13-67°. Both Bi(1)-Se(1) bond lengths are 2.85 Å. There is one shorter (2.74 Å) and two longer (3.20 Å) Bi(1)-Se(2) bond lengths. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a rectangular see-saw-like geometry to one Mn(1), one Mn(2), and two equivalent Bi(1) atoms. In the second Se site, Se(2) is bonded to two equivalent Mn(1) and three equivalent Bi(1) atoms to form a mixture of edge and corner-sharing SeMn2Bi3 square pyramids. I(1) is bonded in an L-shaped geometry to two equivalent Mn(2) atoms.