K3Mn2Cl7 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to four equivalent Cl(3) and eight equivalent Cl(1) atoms to form KCl12 cuboctahedra that share corners with four equivalent K(1)Cl12 cuboctahedra, faces with four equivalent K(1)Cl12 cuboctahedra, and faces with eight equivalent Mn(1)Cl6 octahedra. In the second K site, K(2) is bonded in a 9-coordinate geometry to four equivalent Cl(1) and five equivalent Cl(2) atoms. Mn(1) is bonded to one Cl(2), one Cl(3), and four equivalent Cl(1) atoms to form MnCl6 octahedra that share corners with five equivalent Mn(1)Cl6 octahedra and faces with four equivalent K(1)Cl12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. There are four inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to two equivalent K(1), two equivalent K(2), and two equivalent Mn(1) atoms to form distorted ClK4Mn2 octahedra that share corners with four equivalent Cl(3)K4Mn2 octahedra, corners with six equivalent Cl(2)K5Mn octahedra, corners with eight equivalent Cl(1)K4Mn2 octahedra, edges with three equivalent Cl(1)K4Mn2 octahedra, faces with two equivalent Cl(3)K4Mn2 octahedra, faces with two equivalent Cl(2)K5Mn octahedra, and faces with four equivalent Cl(1)K4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the second Cl site, Cl(2) is bonded to five equivalent K(2) and one Mn(1) atom to form distorted ClK5Mn octahedra that share  a cornercorner with one Cl(3)K4Mn2 octahedra, corners with four equivalent Cl(2)K5Mn octahedra, corners with twelve equivalent Cl(1)K4Mn2 octahedra, edges with eight equivalent Cl(2)K5Mn octahedra, and faces with four equivalent Cl(1)K4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-53°. In the third Cl site, Cl(3) is bonded to four equivalent K(1) and two equivalent Mn(1) atoms to form distorted ClK4Mn2 octahedra that share corners with two equivalent Cl(2)K5Mn octahedra, corners with four equivalent Cl(3)K4Mn2 octahedra, corners with sixteen equivalent Cl(1)K4Mn2 octahedra, edges with four equivalent Cl(3)K4Mn2 octahedra, and faces with eight equivalent Cl(1)K4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the fourth Cl site, Cl(3) is bonded to four equivalent K(1) and two equivalent Mn(1) atoms to form distorted ClK4Mn2 octahedra that share corners with two equivalent Cl(2)K5Mn octahedra, corners with four equivalent Cl(3)K4Mn2 octahedra, corners with sixteen equivalent Cl(1)K4Mn2 octahedra, edges with four equivalent Cl(3)K4Mn2 octahedra, and faces with eight equivalent Cl(1)K4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°.
K3Mn2Cl7 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to four equivalent Cl(3) and eight equivalent Cl(1) atoms to form KCl12 cuboctahedra that share corners with four equivalent K(1)Cl12 cuboctahedra, faces with four equivalent K(1)Cl12 cuboctahedra, and faces with eight equivalent Mn(1)Cl6 octahedra. All K(1)-Cl(3) bond lengths are 3.54 Å. All K(1)-Cl(1) bond lengths are 3.52 Å. In the second K site, K(2) is bonded in a 9-coordinate geometry to four equivalent Cl(1) and five equivalent Cl(2) atoms. All K(2)-Cl(1) bond lengths are 3.31 Å. There is one shorter (3.09 Å) and four longer (3.57 Å) K(2)-Cl(2) bond lengths. Mn(1) is bonded to one Cl(2), one Cl(3), and four equivalent Cl(1) atoms to form MnCl6 octahedra that share corners with five equivalent Mn(1)Cl6 octahedra and faces with four equivalent K(1)Cl12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. The Mn(1)-Cl(2) bond length is 2.48 Å. The Mn(1)-Cl(3) bond length is 2.56 Å. All Mn(1)-Cl(1) bond lengths are 2.51 Å. There are four inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to two equivalent K(1), two equivalent K(2), and two equivalent Mn(1) atoms to form distorted ClK4Mn2 octahedra that share corners with four equivalent Cl(3)K4Mn2 octahedra, corners with six equivalent Cl(2)K5Mn octahedra, corners with eight equivalent Cl(1)K4Mn2 octahedra, edges with three equivalent Cl(1)K4Mn2 octahedra, faces with two equivalent Cl(3)K4Mn2 octahedra, faces with two equivalent Cl(2)K5Mn octahedra, and faces with four equivalent Cl(1)K4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the second Cl site, Cl(2) is bonded to five equivalent K(2) and one Mn(1) atom to form distorted ClK5Mn octahedra that share  a cornercorner with one Cl(3)K4Mn2 octahedra, corners with four equivalent Cl(2)K5Mn octahedra, corners with twelve equivalent Cl(1)K4Mn2 octahedra, edges with eight equivalent Cl(2)K5Mn octahedra, and faces with four equivalent Cl(1)K4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-53°. In the third Cl site, Cl(3) is bonded to four equivalent K(1) and two equivalent Mn(1) atoms to form distorted ClK4Mn2 octahedra that share corners with two equivalent Cl(2)K5Mn octahedra, corners with four equivalent Cl(3)K4Mn2 octahedra, corners with sixteen equivalent Cl(1)K4Mn2 octahedra, edges with four equivalent Cl(3)K4Mn2 octahedra, and faces with eight equivalent Cl(1)K4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the fourth Cl site, Cl(3) is bonded to four equivalent K(1) and two equivalent Mn(1) atoms to form distorted ClK4Mn2 octahedra that share corners with two equivalent Cl(2)K5Mn octahedra, corners with four equivalent Cl(3)K4Mn2 octahedra, corners with sixteen equivalent Cl(1)K4Mn2 octahedra, edges with four equivalent Cl(3)K4Mn2 octahedra, and faces with eight equivalent Cl(1)K4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. All Cl(3)-K(1) bond lengths are 3.54 Å. Both Cl(3)-Mn(1) bond lengths are 2.56 Å.