Cs3Sb2Cl9 crystallizes in the trigonal P321 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded to three equivalent Cl(1) and nine equivalent Cl(2) atoms to form CsCl12 cuboctahedra that share corners with three equivalent Cs(2)Cl12 cuboctahedra, corners with nine equivalent Cs(1)Cl12 cuboctahedra, faces with three equivalent Cs(1)Cl12 cuboctahedra, faces with three equivalent Cs(2)Cl12 cuboctahedra, and faces with five equivalent Sb(1)Cl6 octahedra. In the second Cs site, Cs(2) is bonded to six equivalent Cl(1) and six equivalent Cl(2) atoms to form CsCl12 cuboctahedra that share corners with six equivalent Cs(1)Cl12 cuboctahedra, corners with six equivalent Cs(2)Cl12 cuboctahedra, faces with six equivalent Cs(1)Cl12 cuboctahedra, and faces with six equivalent Sb(1)Cl6 octahedra. Sb(1) is bonded to three equivalent Cl(1) and three equivalent Cl(2) atoms to form SbCl6 octahedra that share corners with three equivalent Sb(1)Cl6 octahedra, faces with three equivalent Cs(2)Cl12 cuboctahedra, and faces with five equivalent Cs(1)Cl12 cuboctahedra. The corner-sharing octahedral tilt angles are 4°. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to two equivalent Cs(1), two equivalent Cs(2), and two equivalent Sb(1) atoms to form a mixture of distorted corner and face-sharing ClCs4Sb2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the second Cl site, Cl(2) is bonded in a distorted single-bond geometry to one Cs(2), three equivalent Cs(1), and one Sb(1) atom.
Cs3Sb2Cl9 crystallizes in the trigonal P321 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded to three equivalent Cl(1) and nine equivalent Cl(2) atoms to form CsCl12 cuboctahedra that share corners with three equivalent Cs(2)Cl12 cuboctahedra, corners with nine equivalent Cs(1)Cl12 cuboctahedra, faces with three equivalent Cs(1)Cl12 cuboctahedra, faces with three equivalent Cs(2)Cl12 cuboctahedra, and faces with five equivalent Sb(1)Cl6 octahedra. All Cs(1)-Cl(1) bond lengths are 3.80 Å. There are a spread of Cs(1)-Cl(2) bond distances ranging from 3.75-3.87 Å. In the second Cs site, Cs(2) is bonded to six equivalent Cl(1) and six equivalent Cl(2) atoms to form CsCl12 cuboctahedra that share corners with six equivalent Cs(1)Cl12 cuboctahedra, corners with six equivalent Cs(2)Cl12 cuboctahedra, faces with six equivalent Cs(1)Cl12 cuboctahedra, and faces with six equivalent Sb(1)Cl6 octahedra. There are three shorter (3.73 Å) and three longer (3.92 Å) Cs(2)-Cl(1) bond lengths. All Cs(2)-Cl(2) bond lengths are 3.89 Å. Sb(1) is bonded to three equivalent Cl(1) and three equivalent Cl(2) atoms to form SbCl6 octahedra that share corners with three equivalent Sb(1)Cl6 octahedra, faces with three equivalent Cs(2)Cl12 cuboctahedra, and faces with five equivalent Cs(1)Cl12 cuboctahedra. The corner-sharing octahedral tilt angles are 4°. All Sb(1)-Cl(1) bond lengths are 2.81 Å. All Sb(1)-Cl(2) bond lengths are 2.51 Å. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to two equivalent Cs(1), two equivalent Cs(2), and two equivalent Sb(1) atoms to form a mixture of distorted corner and face-sharing ClCs4Sb2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the second Cl site, Cl(2) is bonded in a distorted single-bond geometry to one Cs(2), three equivalent Cs(1), and one Sb(1) atom.