Mn2FeSe3 is Caswellsilverite-like structured and crystallizes in the trigonal P-3m1 space group. Mn(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form MnSe6 octahedra that share corners with three equivalent Mn(1)Se6 octahedra, corners with three equivalent Fe(1)Se6 octahedra, edges with three equivalent Fe(1)Se6 octahedra, and edges with nine equivalent Mn(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. Fe(1) is bonded to six equivalent Se(1) atoms to form FeSe6 octahedra that share corners with six equivalent Mn(1)Se6 octahedra, edges with six equivalent Mn(1)Se6 octahedra, and edges with six equivalent Fe(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Mn(1) and three equivalent Fe(1) atoms to form SeMn3Fe3 octahedra that share corners with three equivalent Se(1)Mn3Fe3 octahedra, corners with three equivalent Se(2)Mn6 octahedra, edges with three equivalent Se(2)Mn6 octahedra, and edges with nine equivalent Se(1)Mn3Fe3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Se site, Se(2) is bonded to six equivalent Mn(1) atoms to form SeMn6 octahedra that share corners with six equivalent Se(1)Mn3Fe3 octahedra, edges with six equivalent Se(1)Mn3Fe3 octahedra, and edges with six equivalent Se(2)Mn6 octahedra. The corner-sharing octahedral tilt angles are 1°.
Mn2FeSe3 is Caswellsilverite-like structured and crystallizes in the trigonal P-3m1 space group. Mn(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form MnSe6 octahedra that share corners with three equivalent Mn(1)Se6 octahedra, corners with three equivalent Fe(1)Se6 octahedra, edges with three equivalent Fe(1)Se6 octahedra, and edges with nine equivalent Mn(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. All Mn(1)-Se(1) bond lengths are 2.52 Å. All Mn(1)-Se(2) bond lengths are 2.49 Å. Fe(1) is bonded to six equivalent Se(1) atoms to form FeSe6 octahedra that share corners with six equivalent Mn(1)Se6 octahedra, edges with six equivalent Mn(1)Se6 octahedra, and edges with six equivalent Fe(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 2°. All Fe(1)-Se(1) bond lengths are 2.46 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Mn(1) and three equivalent Fe(1) atoms to form SeMn3Fe3 octahedra that share corners with three equivalent Se(1)Mn3Fe3 octahedra, corners with three equivalent Se(2)Mn6 octahedra, edges with three equivalent Se(2)Mn6 octahedra, and edges with nine equivalent Se(1)Mn3Fe3 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Se site, Se(2) is bonded to six equivalent Mn(1) atoms to form SeMn6 octahedra that share corners with six equivalent Se(1)Mn3Fe3 octahedra, edges with six equivalent Se(1)Mn3Fe3 octahedra, and edges with six equivalent Se(2)Mn6 octahedra. The corner-sharing octahedral tilt angles are 1°.