Sc2Se3 crystallizes in the orthorhombic Fddd space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form a mixture of corner and edge-sharing ScSe6 octahedra. The corner-sharing octahedral tilt angles are 3°. In the second Sc site, Sc(2) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form a mixture of corner and edge-sharing ScSe6 octahedra. The corner-sharing octahedral tilt angles range from 1-3°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a rectangular see-saw-like geometry to two equivalent Sc(1) and two equivalent Sc(2) atoms. In the second Se site, Se(2) is bonded in a rectangular see-saw-like geometry to two equivalent Sc(1) and two equivalent Sc(2) atoms.
Sc2Se3 crystallizes in the orthorhombic Fddd space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form a mixture of corner and edge-sharing ScSe6 octahedra. The corner-sharing octahedral tilt angles are 3°. Both Sc(1)-Se(1) bond lengths are 2.70 Å. There are two shorter (2.69 Å) and two longer (2.74 Å) Sc(1)-Se(2) bond lengths. In the second Sc site, Sc(2) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form a mixture of corner and edge-sharing ScSe6 octahedra. The corner-sharing octahedral tilt angles range from 1-3°. Both Sc(2)-Se(1) bond lengths are 2.73 Å. There are two shorter (2.69 Å) and two longer (2.71 Å) Sc(2)-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 two equivalent Sc(1) and two equivalent Sc(2) atoms. In the second Se site, Se(2) is bonded in a rectangular see-saw-like geometry to two equivalent Sc(1) and two equivalent Sc(2) atoms.