Na3BrCl2 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one Br(1) and five equivalent Cl(1) atoms to form NaBrCl5 octahedra that share  a cornercorner with one Na(2)Br4Cl2 octahedra, corners with five equivalent Na(1)BrCl5 octahedra, edges with four equivalent Na(2)Br4Cl2 octahedra, and edges with eight equivalent Na(1)BrCl5 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Na site, Na(2) is bonded to four equivalent Br(1) and two equivalent Cl(1) atoms to form NaBr4Cl2 octahedra that share corners with two equivalent Na(1)BrCl5 octahedra, corners with four equivalent Na(2)Br4Cl2 octahedra, edges with four equivalent Na(2)Br4Cl2 octahedra, and edges with eight equivalent Na(1)BrCl5 octahedra. The corner-sharing octahedra are not tilted. Br(1) is bonded to two equivalent Na(1) and four equivalent Na(2) atoms to form BrNa6 octahedra that share corners with two equivalent Cl(1)Na6 octahedra, corners with four equivalent Br(1)Na6 octahedra, edges with four equivalent Br(1)Na6 octahedra, and edges with eight equivalent Cl(1)Na6 octahedra. The corner-sharing octahedra are not tilted. Cl(1) is bonded to one Na(2) and five equivalent Na(1) atoms to form ClNa6 octahedra that share  a cornercorner with one Br(1)Na6 octahedra, corners with five equivalent Cl(1)Na6 octahedra, edges with four equivalent Br(1)Na6 octahedra, and edges with eight equivalent Cl(1)Na6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°.
Na3BrCl2 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one Br(1) and five equivalent Cl(1) atoms to form NaBrCl5 octahedra that share  a cornercorner with one Na(2)Br4Cl2 octahedra, corners with five equivalent Na(1)BrCl5 octahedra, edges with four equivalent Na(2)Br4Cl2 octahedra, and edges with eight equivalent Na(1)BrCl5 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. The Na(1)-Br(1) bond length is 2.93 Å. There is one shorter (2.76 Å) and four longer (2.85 Å) Na(1)-Cl(1) bond lengths. In the second Na site, Na(2) is bonded to four equivalent Br(1) and two equivalent Cl(1) atoms to form NaBr4Cl2 octahedra that share corners with two equivalent Na(1)BrCl5 octahedra, corners with four equivalent Na(2)Br4Cl2 octahedra, edges with four equivalent Na(2)Br4Cl2 octahedra, and edges with eight equivalent Na(1)BrCl5 octahedra. The corner-sharing octahedra are not tilted. All Na(2)-Br(1) bond lengths are 2.85 Å. Both Na(2)-Cl(1) bond lengths are 2.87 Å. Br(1) is bonded to two equivalent Na(1) and four equivalent Na(2) atoms to form BrNa6 octahedra that share corners with two equivalent Cl(1)Na6 octahedra, corners with four equivalent Br(1)Na6 octahedra, edges with four equivalent Br(1)Na6 octahedra, and edges with eight equivalent Cl(1)Na6 octahedra. The corner-sharing octahedra are not tilted. Cl(1) is bonded to one Na(2) and five equivalent Na(1) atoms to form ClNa6 octahedra that share  a cornercorner with one Br(1)Na6 octahedra, corners with five equivalent Cl(1)Na6 octahedra, edges with four equivalent Br(1)Na6 octahedra, and edges with eight equivalent Cl(1)Na6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°.