Na3SbSe3 crystallizes in the cubic P2_13 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to six equivalent Se(1) atoms. In the second Na site, Na(2) is bonded to six equivalent Se(1) atoms to form distorted corner-sharing NaSe6 octahedra. The corner-sharing octahedral tilt angles are 46°. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to six equivalent Se(1) atoms. Sb(1) is bonded in a 3-coordinate geometry to three equivalent Se(1) atoms. Se(1) is bonded to two equivalent Na(1), two equivalent Na(2), two equivalent Na(3), and one Sb(1) atom to form a mixture of distorted corner, edge, and face-sharing SeNa6Sb pentagonal bipyramids.
Na3SbSe3 crystallizes in the cubic P2_13 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to six equivalent Se(1) atoms. There are three shorter (3.16 Å) and three longer (3.19 Å) Na(1)-Se(1) bond lengths. In the second Na site, Na(2) is bonded to six equivalent Se(1) atoms to form distorted corner-sharing NaSe6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are three shorter (2.99 Å) and three longer (3.17 Å) Na(2)-Se(1) bond lengths. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to six equivalent Se(1) atoms. There are three shorter (2.98 Å) and three longer (3.21 Å) Na(3)-Se(1) bond lengths. Sb(1) is bonded in a 3-coordinate geometry to three equivalent Se(1) atoms. All Sb(1)-Se(1) bond lengths are 2.58 Å. Se(1) is bonded to two equivalent Na(1), two equivalent Na(2), two equivalent Na(3), and one Sb(1) atom to form a mixture of distorted corner, edge, and face-sharing SeNa6Sb pentagonal bipyramids.