K2CeBr5 crystallizes in the orthorhombic Pnma space group. K(1) is bonded in a 8-coordinate geometry to two equivalent Br(1), two equivalent Br(2), two equivalent Br(3), and two equivalent Br(4) atoms. Ce(1) is bonded to one Br(1), one Br(3), one Br(4), and four equivalent Br(2) atoms to form distorted edge-sharing CeBr7 pentagonal bipyramids. There are four inequivalent Br sites. In the first Br site, Br(1) is bonded to four equivalent K(1) and one Ce(1) atom to form distorted BrK4Ce trigonal bipyramids that share  a cornercorner with one Br(4)K4Ce trigonal bipyramid, corners with four equivalent Br(1)K4Ce trigonal bipyramids, corners with five equivalent Br(3)K4Ce trigonal bipyramids, corners with four equivalent Br(2)K2Ce2 trigonal pyramids, edges with two equivalent Br(3)K4Ce trigonal bipyramids, edges with four equivalent Br(4)K4Ce trigonal bipyramids, and edges with four equivalent Br(2)K2Ce2 trigonal pyramids. In the second Br site, Br(2) is bonded to two equivalent K(1) and two equivalent Ce(1) atoms to form distorted BrK2Ce2 trigonal pyramids that share corners with two equivalent Br(1)K4Ce trigonal bipyramids, corners with two equivalent Br(4)K4Ce trigonal bipyramids, corners with four equivalent Br(3)K4Ce trigonal bipyramids, corners with six equivalent Br(2)K2Ce2 trigonal pyramids,  an edgeedge with one Br(3)K4Ce trigonal bipyramid, edges with two equivalent Br(1)K4Ce trigonal bipyramids, edges with two equivalent Br(4)K4Ce trigonal bipyramids, and  an edgeedge with one Br(2)K2Ce2 trigonal pyramid. In the third Br site, Br(3) is bonded to four equivalent K(1) and one Ce(1) atom to form BrK4Ce trigonal bipyramids that share corners with four equivalent Br(4)K4Ce trigonal bipyramids, corners with five equivalent Br(1)K4Ce trigonal bipyramids, corners with eight equivalent Br(2)K2Ce2 trigonal pyramids,  an edgeedge with one Br(4)K4Ce trigonal bipyramid, edges with two equivalent Br(1)K4Ce trigonal bipyramids, edges with two equivalent Br(3)K4Ce trigonal bipyramids, edges with two equivalent Br(2)K2Ce2 trigonal pyramids, and  a faceface with one Br(4)K4Ce trigonal bipyramid. In the fourth Br site, Br(4) is bonded to four equivalent K(1) and one Ce(1) atom to form BrK4Ce trigonal bipyramids that share  a cornercorner with one Br(1)K4Ce trigonal bipyramid, corners with four equivalent Br(3)K4Ce trigonal bipyramids, corners with four equivalent Br(4)K4Ce trigonal bipyramids, corners with four equivalent Br(2)K2Ce2 trigonal pyramids,  an edgeedge with one Br(3)K4Ce trigonal bipyramid, edges with four equivalent Br(1)K4Ce trigonal bipyramids, edges with four equivalent Br(2)K2Ce2 trigonal pyramids, and  a faceface with one Br(3)K4Ce trigonal bipyramid.
K2CeBr5 crystallizes in the orthorhombic Pnma space group. K(1) is bonded in a 8-coordinate geometry to two equivalent Br(1), two equivalent Br(2), two equivalent Br(3), and two equivalent Br(4) atoms. There is one shorter (3.42 Å) and one longer (3.53 Å) K(1)-Br(1) bond length. There is one shorter (3.49 Å) and one longer (3.52 Å) K(1)-Br(2) bond length. There is one shorter (3.33 Å) and one longer (3.37 Å) K(1)-Br(3) bond length. There is one shorter (3.35 Å) and one longer (3.38 Å) K(1)-Br(4) bond length. Ce(1) is bonded to one Br(1), one Br(3), one Br(4), and four equivalent Br(2) atoms to form distorted edge-sharing CeBr7 pentagonal bipyramids. The Ce(1)-Br(1) bond length is 2.95 Å. The Ce(1)-Br(3) bond length is 3.00 Å. The Ce(1)-Br(4) bond length is 2.97 Å. There are two shorter (2.99 Å) and two longer (3.05 Å) Ce(1)-Br(2) bond lengths. There are four inequivalent Br sites. In the first Br site, Br(1) is bonded to four equivalent K(1) and one Ce(1) atom to form distorted BrK4Ce trigonal bipyramids that share  a cornercorner with one Br(4)K4Ce trigonal bipyramid, corners with four equivalent Br(1)K4Ce trigonal bipyramids, corners with five equivalent Br(3)K4Ce trigonal bipyramids, corners with four equivalent Br(2)K2Ce2 trigonal pyramids, edges with two equivalent Br(3)K4Ce trigonal bipyramids, edges with four equivalent Br(4)K4Ce trigonal bipyramids, and edges with four equivalent Br(2)K2Ce2 trigonal pyramids. In the second Br site, Br(2) is bonded to two equivalent K(1) and two equivalent Ce(1) atoms to form distorted BrK2Ce2 trigonal pyramids that share corners with two equivalent Br(1)K4Ce trigonal bipyramids, corners with two equivalent Br(4)K4Ce trigonal bipyramids, corners with four equivalent Br(3)K4Ce trigonal bipyramids, corners with six equivalent Br(2)K2Ce2 trigonal pyramids,  an edgeedge with one Br(3)K4Ce trigonal bipyramid, edges with two equivalent Br(1)K4Ce trigonal bipyramids, edges with two equivalent Br(4)K4Ce trigonal bipyramids, and  an edgeedge with one Br(2)K2Ce2 trigonal pyramid. In the third Br site, Br(3) is bonded to four equivalent K(1) and one Ce(1) atom to form BrK4Ce trigonal bipyramids that share corners with four equivalent Br(4)K4Ce trigonal bipyramids, corners with five equivalent Br(1)K4Ce trigonal bipyramids, corners with eight equivalent Br(2)K2Ce2 trigonal pyramids,  an edgeedge with one Br(4)K4Ce trigonal bipyramid, edges with two equivalent Br(1)K4Ce trigonal bipyramids, edges with two equivalent Br(3)K4Ce trigonal bipyramids, edges with two equivalent Br(2)K2Ce2 trigonal pyramids, and  a faceface with one Br(4)K4Ce trigonal bipyramid. In the fourth Br site, Br(4) is bonded to four equivalent K(1) and one Ce(1) atom to form BrK4Ce trigonal bipyramids that share  a cornercorner with one Br(1)K4Ce trigonal bipyramid, corners with four equivalent Br(3)K4Ce trigonal bipyramids, corners with four equivalent Br(4)K4Ce trigonal bipyramids, corners with four equivalent Br(2)K2Ce2 trigonal pyramids,  an edgeedge with one Br(3)K4Ce trigonal bipyramid, edges with four equivalent Br(1)K4Ce trigonal bipyramids, edges with four equivalent Br(2)K2Ce2 trigonal pyramids, and  a faceface with one Br(3)K4Ce trigonal bipyramid.