CsVI3 crystallizes in the hexagonal P6_3/mmc space group. Cs(1) is bonded to twelve equivalent I(1) atoms to form CsI12 cuboctahedra that share corners with six equivalent Cs(1)I12 cuboctahedra, corners with six equivalent V(1)I6 octahedra, faces with eight equivalent Cs(1)I12 cuboctahedra, and faces with six equivalent V(1)I6 octahedra. The corner-sharing octahedral tilt angles are 17°. V(1) is bonded to six equivalent I(1) atoms to form VI6 octahedra that share corners with six equivalent Cs(1)I12 cuboctahedra, faces with six equivalent Cs(1)I12 cuboctahedra, and faces with two equivalent V(1)I6 octahedra. I(1) is bonded to four equivalent Cs(1) and two equivalent V(1) atoms to form a mixture of distorted edge, face, and corner-sharing ICs4V2 octahedra. The corner-sharing octahedral tilt angles range from 0-71°.
CsVI3 crystallizes in the hexagonal P6_3/mmc space group. Cs(1) is bonded to twelve equivalent I(1) atoms to form CsI12 cuboctahedra that share corners with six equivalent Cs(1)I12 cuboctahedra, corners with six equivalent V(1)I6 octahedra, faces with eight equivalent Cs(1)I12 cuboctahedra, and faces with six equivalent V(1)I6 octahedra. The corner-sharing octahedral tilt angles are 17°. There are six shorter (4.12 Å) and six longer (4.26 Å) Cs(1)-I(1) bond lengths. V(1) is bonded to six equivalent I(1) atoms to form VI6 octahedra that share corners with six equivalent Cs(1)I12 cuboctahedra, faces with six equivalent Cs(1)I12 cuboctahedra, and faces with two equivalent V(1)I6 octahedra. All V(1)-I(1) bond lengths are 2.87 Å. I(1) is bonded to four equivalent Cs(1) and two equivalent V(1) atoms to form a mixture of distorted edge, face, and corner-sharing ICs4V2 octahedra. The corner-sharing octahedral tilt angles range from 0-71°.