NaAsSe2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. Na(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form NaSe6 octahedra that share corners with six equivalent Na(1)Se6 octahedra, edges with four equivalent Na(1)Se6 octahedra, and edges with eight equivalent As(1)Se6 octahedra. The corner-sharing octahedra are not tilted. As(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form AsSe6 octahedra that share corners with six equivalent As(1)Se6 octahedra, edges with four equivalent As(1)Se6 octahedra, and edges with eight equivalent Na(1)Se6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Na(1) and four equivalent As(1) atoms to form SeNa2As4 octahedra that share corners with six equivalent Se(1)Na2As4 octahedra, edges with four equivalent Se(1)Na2As4 octahedra, and edges with eight equivalent Se(2)Na4As2 octahedra. The corner-sharing octahedra are not tilted. In the second Se site, Se(2) is bonded to four equivalent Na(1) and two equivalent As(1) atoms to form SeNa4As2 octahedra that share corners with six equivalent Se(2)Na4As2 octahedra, edges with four equivalent Se(2)Na4As2 octahedra, and edges with eight equivalent Se(1)Na2As4 octahedra. The corner-sharing octahedra are not tilted.
NaAsSe2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. Na(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form NaSe6 octahedra that share corners with six equivalent Na(1)Se6 octahedra, edges with four equivalent Na(1)Se6 octahedra, and edges with eight equivalent As(1)Se6 octahedra. The corner-sharing octahedra are not tilted. Both Na(1)-Se(1) bond lengths are 2.78 Å. All Na(1)-Se(2) bond lengths are 2.83 Å. As(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form AsSe6 octahedra that share corners with six equivalent As(1)Se6 octahedra, edges with four equivalent As(1)Se6 octahedra, and edges with eight equivalent Na(1)Se6 octahedra. The corner-sharing octahedra are not tilted. Both As(1)-Se(2) bond lengths are 2.78 Å. All As(1)-Se(1) bond lengths are 2.83 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Na(1) and four equivalent As(1) atoms to form SeNa2As4 octahedra that share corners with six equivalent Se(1)Na2As4 octahedra, edges with four equivalent Se(1)Na2As4 octahedra, and edges with eight equivalent Se(2)Na4As2 octahedra. The corner-sharing octahedra are not tilted. In the second Se site, Se(2) is bonded to four equivalent Na(1) and two equivalent As(1) atoms to form SeNa4As2 octahedra that share corners with six equivalent Se(2)Na4As2 octahedra, edges with four equivalent Se(2)Na4As2 octahedra, and edges with eight equivalent Se(1)Na2As4 octahedra. The corner-sharing octahedra are not tilted.