K3Nd3Br10 crystallizes in the monoclinic P2_1 space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one Br(1), one Br(10), one Br(2), one Br(5), one Br(6), one Br(7), one Br(8), and one Br(9) atom. In the second K site, K(2) is bonded in a 8-coordinate geometry to one Br(10), one Br(3), one Br(4), one Br(5), one Br(6), one Br(7), one Br(8), and one Br(9) atom. In the third K site, K(3) is bonded in a 8-coordinate geometry to one Br(10), one Br(3), one Br(4), one Br(5), one Br(6), one Br(7), one Br(8), and one Br(9) atom. There are three inequivalent Nd sites. In the first Nd site, Nd(1) is bonded to one Br(1), one Br(2), one Br(3), one Br(4), one Br(5), one Br(8), and one Br(9) atom to form distorted edge-sharing NdBr7 pentagonal bipyramids. In the second Nd site, Nd(2) is bonded to one Br(1), one Br(10), one Br(2), one Br(3), one Br(4), one Br(6), and one Br(7) atom to form distorted edge-sharing NdBr7 pentagonal bipyramids. In the third Nd site, Nd(3) is bonded in a 8-coordinate geometry to one Br(1), one Br(10), one Br(2), one Br(5), one Br(6), one Br(7), one Br(8), and one Br(9) atom. There are ten inequivalent Br sites. In the first Br site, Br(1) is bonded to one K(1), one Nd(1), one Nd(2), and one Nd(3) atom to form distorted BrKNd3 trigonal pyramids that share corners with three equivalent Br(7)K3Nd2 square pyramids, corners with four equivalent Br(2)KNd3 tetrahedra,  a cornercorner with one Br(10)K3Nd2 trigonal bipyramid,  a cornercorner with one Br(8)K3Nd2 trigonal bipyramid,  a cornercorner with one Br(9)K3Nd2 trigonal bipyramid, corners with two equivalent Br(4)K2Nd2 trigonal pyramids,  an edgeedge with one Br(3)K2Nd2 tetrahedra,  an edgeedge with one Br(10)K3Nd2 trigonal bipyramid,  an edgeedge with one Br(8)K3Nd2 trigonal bipyramid, and  an edgeedge with one Br(9)K3Nd2 trigonal bipyramid. In the second Br site, Br(2) is bonded to one K(1), one Nd(1), one Nd(2), and one Nd(3) atom to form BrKNd3 tetrahedra that share  a cornercorner with one Br(7)K3Nd2 square pyramid, corners with two equivalent Br(3)K2Nd2 tetrahedra,  a cornercorner with one Br(10)K3Nd2 trigonal bipyramid,  a cornercorner with one Br(9)K3Nd2 trigonal bipyramid, corners with three equivalent Br(8)K3Nd2 trigonal bipyramids, corners with four equivalent Br(1)KNd3 trigonal pyramids,  an edgeedge with one Br(7)K3Nd2 square pyramid,  an edgeedge with one Br(10)K3Nd2 trigonal bipyramid,  an edgeedge with one Br(9)K3Nd2 trigonal bipyramid, and  an edgeedge with one Br(4)K2Nd2 trigonal pyramid. In the third Br site, Br(3) is bonded to one K(2), one K(3), one Nd(1), and one Nd(2) atom to form distorted BrK2Nd2 tetrahedra that share  a cornercorner with one Br(7)K3Nd2 square pyramid, corners with two equivalent Br(2)KNd3 tetrahedra,  a cornercorner with one Br(10)K3Nd2 trigonal bipyramid,  a cornercorner with one Br(9)K3Nd2 trigonal bipyramid, corners with three equivalent Br(8)K3Nd2 trigonal bipyramids, corners with four equivalent Br(4)K2Nd2 trigonal pyramids,  an edgeedge with one Br(7)K3Nd2 square pyramid,  an edgeedge with one Br(10)K3Nd2 trigonal bipyramid,  an edgeedge with one Br(9)K3Nd2 trigonal bipyramid, and  an edgeedge with one Br(1)KNd3 trigonal pyramid. In the fourth Br site, Br(4) is bonded to one K(2), one K(3), one Nd(1), and one Nd(2) atom to form distorted BrK2Nd2 trigonal pyramids that share corners with three equivalent Br(7)K3Nd2 square pyramids, corners with four equivalent Br(3)K2Nd2 tetrahedra,  a cornercorner with one Br(10)K3Nd2 trigonal bipyramid,  a cornercorner with one Br(8)K3Nd2 trigonal bipyramid,  a cornercorner with one Br(9)K3Nd2 trigonal bipyramid, corners with two equivalent Br(1)KNd3 trigonal pyramids,  an edgeedge with one Br(2)KNd3 tetrahedra,  an edgeedge with one Br(10)K3Nd2 trigonal bipyramid,  an edgeedge with one Br(8)K3Nd2 trigonal bipyramid, and  an edgeedge with one Br(9)K3Nd2 trigonal bipyramid. In the fifth Br site, Br(5) is bonded in a 5-coordinate geometry to one K(1), one K(2), one K(3), one Nd(1), and one Nd(3) atom. In the sixth Br site, Br(6) is bonded in a 5-coordinate geometry to one K(1), one K(2), one K(3), one Nd(2), and one Nd(3) atom. In the seventh Br site, Br(7) is bonded to one K(1), one K(2), one K(3), one Nd(2), and one Nd(3) atom to form distorted BrK3Nd2 square pyramids that share  a cornercorner with one Br(3)K2Nd2 tetrahedra,  a cornercorner with one Br(2)KNd3 tetrahedra, corners with four equivalent Br(9)K3Nd2 trigonal bipyramids, corners with three equivalent Br(4)K2Nd2 trigonal pyramids, corners with three equivalent Br(1)KNd3 trigonal pyramids,  an edgeedge with one Br(3)K2Nd2 tetrahedra,  an edgeedge with one Br(2)KNd3 tetrahedra,  an edgeedge with one Br(10)K3Nd2 trigonal bipyramid, edges with two equivalent Br(8)K3Nd2 trigonal bipyramids, and  a faceface with one Br(10)K3Nd2 trigonal bipyramid. In the eighth Br site, Br(8) is bonded to one K(1), one K(2), one K(3), one Nd(1), and one Nd(3) atom to form distorted BrK3Nd2 trigonal bipyramids that share corners with three equivalent Br(3)K2Nd2 tetrahedra, corners with three equivalent Br(2)KNd3 tetrahedra, corners with four equivalent Br(10)K3Nd2 trigonal bipyramids,  a cornercorner with one Br(4)K2Nd2 trigonal pyramid,  a cornercorner with one Br(1)KNd3 trigonal pyramid, edges with two equivalent Br(7)K3Nd2 square pyramids,  an edgeedge with one Br(9)K3Nd2 trigonal bipyramid,  an edgeedge with one Br(4)K2Nd2 trigonal pyramid,  an edgeedge with one Br(1)KNd3 trigonal pyramid, and  a faceface with one Br(9)K3Nd2 trigonal bipyramid. In the ninth Br site, Br(9) is bonded to one K(1), one K(2), one K(3), one Nd(1), and one Nd(3) atom to form distorted BrK3Nd2 trigonal bipyramids that share corners with four equivalent Br(7)K3Nd2 square pyramids,  a cornercorner with one Br(3)K2Nd2 tetrahedra,  a cornercorner with one Br(2)KNd3 tetrahedra, corners with four equivalent Br(10)K3Nd2 trigonal bipyramids,  a cornercorner with one Br(4)K2Nd2 trigonal pyramid,  a cornercorner with one Br(1)KNd3 trigonal pyramid,  an edgeedge with one Br(3)K2Nd2 tetrahedra,  an edgeedge with one Br(2)KNd3 tetrahedra,  an edgeedge with one Br(8)K3Nd2 trigonal bipyramid,  an edgeedge with one Br(4)K2Nd2 trigonal pyramid,  an edgeedge with one Br(1)KNd3 trigonal pyramid, and  a faceface with one Br(8)K3Nd2 trigonal bipyramid. In the tenth Br site, Br(10) is bonded to one K(1), one K(2), one K(3), one Nd(2), and one Nd(3) atom to form distorted BrK3Nd2 trigonal bipyramids that share  a cornercorner with one Br(3)K2Nd2 tetrahedra,  a cornercorner with one Br(2)KNd3 tetrahedra, corners with four equivalent Br(8)K3Nd2 trigonal bipyramids, corners with four equivalent Br(9)K3Nd2 trigonal bipyramids,  a cornercorner with one Br(4)K2Nd2 trigonal pyramid,  a cornercorner with one Br(1)KNd3 trigonal pyramid,  an edgeedge with one Br(7)K3Nd2 square pyramid,  an edgeedge with one Br(3)K2Nd2 tetrahedra,  an edgeedge with one Br(2)KNd3 tetrahedra,  an edgeedge with one Br(4)K2Nd2 trigonal pyramid,  an edgeedge with one Br(1)KNd3 trigonal pyramid, and  a faceface with one Br(7)K3Nd2 square pyramid.
K3Nd3Br10 crystallizes in the monoclinic P2_1 space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one Br(1), one Br(10), one Br(2), one Br(5), one Br(6), one Br(7), one Br(8), and one Br(9) atom. The K(1)-Br(1) bond length is 3.48 Å. The K(1)-Br(10) bond length is 3.42 Å. The K(1)-Br(2) bond length is 3.34 Å. The K(1)-Br(5) bond length is 3.45 Å. The K(1)-Br(6) bond length is 3.37 Å. The K(1)-Br(7) bond length is 3.56 Å. The K(1)-Br(8) bond length is 3.59 Å. The K(1)-Br(9) bond length is 3.28 Å. In the second K site, K(2) is bonded in a 8-coordinate geometry to one Br(10), one Br(3), one Br(4), one Br(5), one Br(6), one Br(7), one Br(8), and one Br(9) atom. The K(2)-Br(10) bond length is 3.28 Å. The K(2)-Br(3) bond length is 3.46 Å. The K(2)-Br(4) bond length is 3.40 Å. The K(2)-Br(5) bond length is 3.83 Å. The K(2)-Br(6) bond length is 3.87 Å. The K(2)-Br(7) bond length is 3.40 Å. The K(2)-Br(8) bond length is 3.29 Å. The K(2)-Br(9) bond length is 3.38 Å. In the third K site, K(3) is bonded in a 8-coordinate geometry to one Br(10), one Br(3), one Br(4), one Br(5), one Br(6), one Br(7), one Br(8), and one Br(9) atom. The K(3)-Br(10) bond length is 3.48 Å. The K(3)-Br(3) bond length is 3.30 Å. The K(3)-Br(4) bond length is 3.38 Å. The K(3)-Br(5) bond length is 3.35 Å. The K(3)-Br(6) bond length is 3.39 Å. The K(3)-Br(7) bond length is 3.38 Å. The K(3)-Br(8) bond length is 3.44 Å. The K(3)-Br(9) bond length is 3.46 Å. There are three inequivalent Nd sites. In the first Nd site, Nd(1) is bonded to one Br(1), one Br(2), one Br(3), one Br(4), one Br(5), one Br(8), and one Br(9) atom to form distorted edge-sharing NdBr7 pentagonal bipyramids. The Nd(1)-Br(1) bond length is 3.04 Å. The Nd(1)-Br(2) bond length is 3.06 Å. The Nd(1)-Br(3) bond length is 3.01 Å. The Nd(1)-Br(4) bond length is 3.00 Å. The Nd(1)-Br(5) bond length is 3.06 Å. The Nd(1)-Br(8) bond length is 3.16 Å. The Nd(1)-Br(9) bond length is 3.07 Å. In the second Nd site, Nd(2) is bonded to one Br(1), one Br(10), one Br(2), one Br(3), one Br(4), one Br(6), and one Br(7) atom to form distorted edge-sharing NdBr7 pentagonal bipyramids. The Nd(2)-Br(1) bond length is 3.04 Å. The Nd(2)-Br(10) bond length is 3.00 Å. The Nd(2)-Br(2) bond length is 3.09 Å. The Nd(2)-Br(3) bond length is 3.00 Å. The Nd(2)-Br(4) bond length is 3.06 Å. The Nd(2)-Br(6) bond length is 3.16 Å. The Nd(2)-Br(7) bond length is 3.03 Å. In the third Nd site, Nd(3) is bonded in a 8-coordinate geometry to one Br(1), one Br(10), one Br(2), one Br(5), one Br(6), one Br(7), one Br(8), and one Br(9) atom. The Nd(3)-Br(1) bond length is 3.46 Å. The Nd(3)-Br(10) bond length is 3.04 Å. The Nd(3)-Br(2) bond length is 3.26 Å. The Nd(3)-Br(5) bond length is 3.15 Å. The Nd(3)-Br(6) bond length is 3.17 Å. The Nd(3)-Br(7) bond length is 3.03 Å. The Nd(3)-Br(8) bond length is 3.12 Å. The Nd(3)-Br(9) bond length is 3.20 Å. There are ten inequivalent Br sites. In the first Br site, Br(1) is bonded to one K(1), one Nd(1), one Nd(2), and one Nd(3) atom to form distorted BrKNd3 trigonal pyramids that share corners with three equivalent Br(7)K3Nd2 square pyramids, corners with four equivalent Br(2)KNd3 tetrahedra,  a cornercorner with one Br(10)K3Nd2 trigonal bipyramid,  a cornercorner with one Br(8)K3Nd2 trigonal bipyramid,  a cornercorner with one Br(9)K3Nd2 trigonal bipyramid, corners with two equivalent Br(4)K2Nd2 trigonal pyramids,  an edgeedge with one Br(3)K2Nd2 tetrahedra,  an edgeedge with one Br(10)K3Nd2 trigonal bipyramid,  an edgeedge with one Br(8)K3Nd2 trigonal bipyramid, and  an edgeedge with one Br(9)K3Nd2 trigonal bipyramid. In the second Br site, Br(2) is bonded to one K(1), one Nd(1), one Nd(2), and one Nd(3) atom to form BrKNd3 tetrahedra that share  a cornercorner with one Br(7)K3Nd2 square pyramid, corners with two equivalent Br(3)K2Nd2 tetrahedra,  a cornercorner with one Br(10)K3Nd2 trigonal bipyramid,  a cornercorner with one Br(9)K3Nd2 trigonal bipyramid, corners with three equivalent Br(8)K3Nd2 trigonal bipyramids, corners with four equivalent Br(1)KNd3 trigonal pyramids,  an edgeedge with one Br(7)K3Nd2 square pyramid,  an edgeedge with one Br(10)K3Nd2 trigonal bipyramid,  an edgeedge with one Br(9)K3Nd2 trigonal bipyramid, and  an edgeedge with one Br(4)K2Nd2 trigonal pyramid. In the third Br site, Br(3) is bonded to one K(2), one K(3), one Nd(1), and one Nd(2) atom to form distorted BrK2Nd2 tetrahedra that share  a cornercorner with one Br(7)K3Nd2 square pyramid, corners with two equivalent Br(2)KNd3 tetrahedra,  a cornercorner with one Br(10)K3Nd2 trigonal bipyramid,  a cornercorner with one Br(9)K3Nd2 trigonal bipyramid, corners with three equivalent Br(8)K3Nd2 trigonal bipyramids, corners with four equivalent Br(4)K2Nd2 trigonal pyramids,  an edgeedge with one Br(7)K3Nd2 square pyramid,  an edgeedge with one Br(10)K3Nd2 trigonal bipyramid,  an edgeedge with one Br(9)K3Nd2 trigonal bipyramid, and  an edgeedge with one Br(1)KNd3 trigonal pyramid. In the fourth Br site, Br(4) is bonded to one K(2), one K(3), one Nd(1), and one Nd(2) atom to form distorted BrK2Nd2 trigonal pyramids that share corners with three equivalent Br(7)K3Nd2 square pyramids, corners with four equivalent Br(3)K2Nd2 tetrahedra,  a cornercorner with one Br(10)K3Nd2 trigonal bipyramid,  a cornercorner with one Br(8)K3Nd2 trigonal bipyramid,  a cornercorner with one Br(9)K3Nd2 trigonal bipyramid, corners with two equivalent Br(1)KNd3 trigonal pyramids,  an edgeedge with one Br(2)KNd3 tetrahedra,  an edgeedge with one Br(10)K3Nd2 trigonal bipyramid,  an edgeedge with one Br(8)K3Nd2 trigonal bipyramid, and  an edgeedge with one Br(9)K3Nd2 trigonal bipyramid. In the fifth Br site, Br(5) is bonded in a 5-coordinate geometry to one K(1), one K(2), one K(3), one Nd(1), and one Nd(3) atom. In the sixth Br site, Br(6) is bonded in a 5-coordinate geometry to one K(1), one K(2), one K(3), one Nd(2), and one Nd(3) atom. In the seventh Br site, Br(7) is bonded to one K(1), one K(2), one K(3), one Nd(2), and one Nd(3) atom to form distorted BrK3Nd2 square pyramids that share  a cornercorner with one Br(3)K2Nd2 tetrahedra,  a cornercorner with one Br(2)KNd3 tetrahedra, corners with four equivalent Br(9)K3Nd2 trigonal bipyramids, corners with three equivalent Br(4)K2Nd2 trigonal pyramids, corners with three equivalent Br(1)KNd3 trigonal pyramids,  an edgeedge with one Br(3)K2Nd2 tetrahedra,  an edgeedge with one Br(2)KNd3 tetrahedra,  an edgeedge with one Br(10)K3Nd2 trigonal bipyramid, edges with two equivalent Br(8)K3Nd2 trigonal bipyramids, and  a faceface with one Br(10)K3Nd2 trigonal bipyramid. In the eighth Br site, Br(8) is bonded to one K(1), one K(2), one K(3), one Nd(1), and one Nd(3) atom to form distorted BrK3Nd2 trigonal bipyramids that share corners with three equivalent Br(3)K2Nd2 tetrahedra, corners with three equivalent Br(2)KNd3 tetrahedra, corners with four equivalent Br(10)K3Nd2 trigonal bipyramids,  a cornercorner with one Br(4)K2Nd2 trigonal pyramid,  a cornercorner with one Br(1)KNd3 trigonal pyramid, edges with two equivalent Br(7)K3Nd2 square pyramids,  an edgeedge with one Br(9)K3Nd2 trigonal bipyramid,  an edgeedge with one Br(4)K2Nd2 trigonal pyramid,  an edgeedge with one Br(1)KNd3 trigonal pyramid, and  a faceface with one Br(9)K3Nd2 trigonal bipyramid. In the ninth Br site, Br(9) is bonded to one K(1), one K(2), one K(3), one Nd(1), and one Nd(3) atom to form distorted BrK3Nd2 trigonal bipyramids that share corners with four equivalent Br(7)K3Nd2 square pyramids,  a cornercorner with one Br(3)K2Nd2 tetrahedra,  a cornercorner with one Br(2)KNd3 tetrahedra, corners with four equivalent Br(10)K3Nd2 trigonal bipyramids,  a cornercorner with one Br(4)K2Nd2 trigonal pyramid,  a cornercorner with one Br(1)KNd3 trigonal pyramid,  an edgeedge with one Br(3)K2Nd2 tetrahedra,  an edgeedge with one Br(2)KNd3 tetrahedra,  an edgeedge with one Br(8)K3Nd2 trigonal bipyramid,  an edgeedge with one Br(4)K2Nd2 trigonal pyramid,  an edgeedge with one Br(1)KNd3 trigonal pyramid, and  a faceface with one Br(8)K3Nd2 trigonal bipyramid. In the tenth Br site, Br(10) is bonded to one K(1), one K(2), one K(3), one Nd(2), and one Nd(3) atom to form distorted BrK3Nd2 trigonal bipyramids that share  a cornercorner with one Br(3)K2Nd2 tetrahedra,  a cornercorner with one Br(2)KNd3 tetrahedra, corners with four equivalent Br(8)K3Nd2 trigonal bipyramids, corners with four equivalent Br(9)K3Nd2 trigonal bipyramids,  a cornercorner with one Br(4)K2Nd2 trigonal pyramid,  a cornercorner with one Br(1)KNd3 trigonal pyramid,  an edgeedge with one Br(7)K3Nd2 square pyramid,  an edgeedge with one Br(3)K2Nd2 tetrahedra,  an edgeedge with one Br(2)KNd3 tetrahedra,  an edgeedge with one Br(4)K2Nd2 trigonal pyramid,  an edgeedge with one Br(1)KNd3 trigonal pyramid, and  a faceface with one Br(7)K3Nd2 square pyramid.