K4NaCl5 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to one Cl(2), one Cl(3), and four equivalent Cl(1) atoms to form KCl6 octahedra that share  a cornercorner with one K(2)Cl6 octahedra, corners with five equivalent K(1)Cl6 octahedra, edges with four equivalent K(1)Cl6 octahedra, edges with four equivalent K(2)Cl6 octahedra, and edges with four equivalent Na(1)Cl6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the second K site, K(2) is bonded to one Cl(1) and five equivalent Cl(3) atoms to form KCl6 octahedra that share  a cornercorner with one K(1)Cl6 octahedra,  a cornercorner with one Na(1)Cl6 octahedra, corners with four equivalent K(2)Cl6 octahedra, edges with four equivalent K(1)Cl6 octahedra, and edges with eight equivalent K(2)Cl6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. Na(1) is bonded to two equivalent Cl(1) and four equivalent Cl(2) atoms to form NaCl6 octahedra that share corners with two equivalent K(2)Cl6 octahedra, corners with four equivalent Na(1)Cl6 octahedra, edges with four equivalent Na(1)Cl6 octahedra, and edges with eight equivalent K(1)Cl6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to one K(2), four equivalent K(1), and one Na(1) atom to form ClK5Na octahedra that share  a cornercorner with one Cl(3)K6 octahedra, corners with five equivalent Cl(1)K5Na octahedra, edges with four equivalent Cl(2)K2Na4 octahedra, edges with four equivalent Cl(1)K5Na octahedra, and edges with four equivalent Cl(3)K6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the second Cl site, Cl(2) is bonded to two equivalent K(1) and four equivalent Na(1) atoms to form ClK2Na4 octahedra that share corners with two equivalent Cl(3)K6 octahedra, corners with four equivalent Cl(2)K2Na4 octahedra, edges with four equivalent Cl(2)K2Na4 octahedra, and edges with eight equivalent Cl(1)K5Na octahedra. The corner-sharing octahedra are not tilted. In the third Cl site, Cl(3) is bonded to one K(1) and five equivalent K(2) atoms to form ClK6 octahedra that share  a cornercorner with one Cl(2)K2Na4 octahedra,  a cornercorner with one Cl(1)K5Na octahedra, corners with four equivalent Cl(3)K6 octahedra, edges with four equivalent Cl(1)K5Na octahedra, and edges with eight equivalent Cl(3)K6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°.
K4NaCl5 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to one Cl(2), one Cl(3), and four equivalent Cl(1) atoms to form KCl6 octahedra that share  a cornercorner with one K(2)Cl6 octahedra, corners with five equivalent K(1)Cl6 octahedra, edges with four equivalent K(1)Cl6 octahedra, edges with four equivalent K(2)Cl6 octahedra, and edges with four equivalent Na(1)Cl6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. The K(1)-Cl(2) bond length is 3.03 Å. The K(1)-Cl(3) bond length is 3.19 Å. All K(1)-Cl(1) bond lengths are 3.14 Å. In the second K site, K(2) is bonded to one Cl(1) and five equivalent Cl(3) atoms to form KCl6 octahedra that share  a cornercorner with one K(1)Cl6 octahedra,  a cornercorner with one Na(1)Cl6 octahedra, corners with four equivalent K(2)Cl6 octahedra, edges with four equivalent K(1)Cl6 octahedra, and edges with eight equivalent K(2)Cl6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. The K(2)-Cl(1) bond length is 3.25 Å. There are four shorter (3.14 Å) and one longer (3.18 Å) K(2)-Cl(3) bond length. Na(1) is bonded to two equivalent Cl(1) and four equivalent Cl(2) atoms to form NaCl6 octahedra that share corners with two equivalent K(2)Cl6 octahedra, corners with four equivalent Na(1)Cl6 octahedra, edges with four equivalent Na(1)Cl6 octahedra, and edges with eight equivalent K(1)Cl6 octahedra. The corner-sharing octahedra are not tilted. Both Na(1)-Cl(1) bond lengths are 2.92 Å. All Na(1)-Cl(2) bond lengths are 3.14 Å. There are three inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to one K(2), four equivalent K(1), and one Na(1) atom to form ClK5Na octahedra that share  a cornercorner with one Cl(3)K6 octahedra, corners with five equivalent Cl(1)K5Na octahedra, edges with four equivalent Cl(2)K2Na4 octahedra, edges with four equivalent Cl(1)K5Na octahedra, and edges with four equivalent Cl(3)K6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the second Cl site, Cl(2) is bonded to two equivalent K(1) and four equivalent Na(1) atoms to form ClK2Na4 octahedra that share corners with two equivalent Cl(3)K6 octahedra, corners with four equivalent Cl(2)K2Na4 octahedra, edges with four equivalent Cl(2)K2Na4 octahedra, and edges with eight equivalent Cl(1)K5Na octahedra. The corner-sharing octahedra are not tilted. In the third Cl site, Cl(3) is bonded to one K(1) and five equivalent K(2) atoms to form ClK6 octahedra that share  a cornercorner with one Cl(2)K2Na4 octahedra,  a cornercorner with one Cl(1)K5Na octahedra, corners with four equivalent Cl(3)K6 octahedra, edges with four equivalent Cl(1)K5Na octahedra, and edges with eight equivalent Cl(3)K6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°.