CsBr3 crystallizes in the orthorhombic Pnma space group. Cs(1) is bonded in a 10-coordinate geometry to two equivalent Br(2), four equivalent Br(1), and four equivalent Br(3) atoms. There are three inequivalent Br sites. In the first Br site, Br(2) is bonded to two equivalent Cs(1), one Br(1), and one Br(3) atom to form distorted BrCs2Br2 tetrahedra that share corners with two equivalent Br(2)Cs2Br2 tetrahedra, corners with six equivalent Br(3)Cs4Br trigonal bipyramids, and  an edgeedge with one Br(3)Cs4Br trigonal bipyramid. In the second Br site, Br(1) is bonded in a 5-coordinate geometry to four equivalent Cs(1) and one Br(2) atom. In the third Br site, Br(3) is bonded to four equivalent Cs(1) and one Br(2) atom to form distorted BrCs4Br trigonal bipyramids that share corners with six equivalent Br(2)Cs2Br2 tetrahedra, corners with eight equivalent Br(3)Cs4Br trigonal bipyramids,  an edgeedge with one Br(2)Cs2Br2 tetrahedra, and edges with two equivalent Br(3)Cs4Br trigonal bipyramids.
CsBr3 crystallizes in the orthorhombic Pnma space group. Cs(1) is bonded in a 10-coordinate geometry to two equivalent Br(2), four equivalent Br(1), and four equivalent Br(3) atoms. Both Cs(1)-Br(2) bond lengths are 3.84 Å. There are a spread of Cs(1)-Br(1) bond distances ranging from 3.59-3.70 Å. There are a spread of Cs(1)-Br(3) bond distances ranging from 3.75-4.14 Å. There are three inequivalent Br sites. In the first Br site, Br(2) is bonded to two equivalent Cs(1), one Br(1), and one Br(3) atom to form distorted BrCs2Br2 tetrahedra that share corners with two equivalent Br(2)Cs2Br2 tetrahedra, corners with six equivalent Br(3)Cs4Br trigonal bipyramids, and  an edgeedge with one Br(3)Cs4Br trigonal bipyramid. The Br(2)-Br(1) bond length is 2.65 Å. The Br(2)-Br(3) bond length is 2.50 Å. In the second Br site, Br(1) is bonded in a 5-coordinate geometry to four equivalent Cs(1) and one Br(2) atom. In the third Br site, Br(3) is bonded to four equivalent Cs(1) and one Br(2) atom to form distorted BrCs4Br trigonal bipyramids that share corners with six equivalent Br(2)Cs2Br2 tetrahedra, corners with eight equivalent Br(3)Cs4Br trigonal bipyramids,  an edgeedge with one Br(2)Cs2Br2 tetrahedra, and edges with two equivalent Br(3)Cs4Br trigonal bipyramids.