Ba4Ge2PbSe8Br2 crystallizes in the orthorhombic Pmn2_1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one Se(3), one Se(4), one Se(5), one Se(6), two equivalent Se(1), and two equivalent Br(1) atoms. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to one Se(3), one Se(4), one Se(5), one Se(6), two equivalent Se(2), and two equivalent Br(2) atoms. Pb(1) is bonded to one Se(2), two equivalent Se(5), two equivalent Se(6), and one Br(1) atom to form distorted PbSe5Br octahedra that share corners with three equivalent Ge(2)Se4 tetrahedra and  an edgeedge with one Ge(1)Se4 tetrahedra. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one Se(1), one Se(3), and two equivalent Se(5) atoms to form GeSe4 tetrahedra that share  an edgeedge with one Pb(1)Se5Br octahedra. In the second Ge site, Ge(2) is bonded to one Se(2), one Se(4), and two equivalent Se(6) atoms to form GeSe4 tetrahedra that share corners with three equivalent Pb(1)Se5Br octahedra. The corner-sharing octahedral tilt angles range from 5-16°. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded to four equivalent Ba(1) and one Ge(1) atom to form distorted SeBa4Ge square pyramids that share corners with two equivalent Se(3)Ba4Ge square pyramids, corners with two equivalent Se(4)Ba4Ge square pyramids, corners with four equivalent Se(1)Ba4Ge square pyramids, corners with two equivalent Se(5)Ba2GePb trigonal pyramids,  an edgeedge with one Se(4)Ba4Ge square pyramid, edges with four equivalent Br(1)Ba4Pb square pyramids, edges with two equivalent Se(5)Ba2GePb trigonal pyramids, and  a faceface with one Se(3)Ba4Ge square pyramid. In the second Se site, Se(2) is bonded to four equivalent Ba(2), one Pb(1), and one Ge(2) atom to form distorted SeBa4GePb octahedra that share corners with four equivalent Se(2)Ba4GePb octahedra,  a cornercorner with one Br(1)Ba4Pb square pyramid, corners with two equivalent Se(3)Ba4Ge square pyramids, corners with two equivalent Se(4)Ba4Ge square pyramids, corners with two equivalent Se(5)Ba2GePb trigonal pyramids,  an edgeedge with one Se(3)Ba4Ge square pyramid, edges with two equivalent Se(5)Ba2GePb trigonal pyramids, and  a faceface with one Se(4)Ba4Ge square pyramid. The corner-sharing octahedral tilt angles are 31°. In the third Se site, Se(3) is bonded to two equivalent Ba(1), two equivalent Ba(2), and one Ge(1) atom to form distorted SeBa4Ge square pyramids that share corners with two equivalent Se(2)Ba4GePb octahedra, corners with two equivalent Se(1)Ba4Ge square pyramids, corners with two equivalent Br(1)Ba4Pb square pyramids, corners with two equivalent Se(5)Ba2GePb trigonal pyramids,  an edgeedge with one Se(2)Ba4GePb octahedra,  an edgeedge with one Br(1)Ba4Pb square pyramid, edges with two equivalent Se(4)Ba4Ge square pyramids, edges with two equivalent Se(5)Ba2GePb trigonal pyramids, and  a faceface with one Se(1)Ba4Ge square pyramid. The corner-sharing octahedral tilt angles are 59°. In the fourth Se site, Se(4) is bonded to two equivalent Ba(1), two equivalent Ba(2), and one Ge(2) atom to form distorted SeBa4Ge square pyramids that share corners with two equivalent Se(2)Ba4GePb octahedra, corners with two equivalent Se(1)Ba4Ge square pyramids, corners with two equivalent Br(1)Ba4Pb square pyramids, corners with four equivalent Se(5)Ba2GePb trigonal pyramids,  an edgeedge with one Se(1)Ba4Ge square pyramid,  an edgeedge with one Br(1)Ba4Pb square pyramid, edges with two equivalent Se(3)Ba4Ge square pyramids, and  a faceface with one Se(2)Ba4GePb octahedra. The corner-sharing octahedral tilt angles are 43°. In the fifth Se site, Se(5) is bonded to one Ba(1), one Ba(2), one Pb(1), and one Ge(1) atom to form distorted SeBa2GePb trigonal pyramids that share  a cornercorner with one Se(2)Ba4GePb octahedra,  a cornercorner with one Se(1)Ba4Ge square pyramid,  a cornercorner with one Se(3)Ba4Ge square pyramid,  a cornercorner with one Br(1)Ba4Pb square pyramid, corners with two equivalent Se(4)Ba4Ge square pyramids,  an edgeedge with one Se(2)Ba4GePb octahedra,  an edgeedge with one Se(1)Ba4Ge square pyramid,  an edgeedge with one Se(3)Ba4Ge square pyramid,  an edgeedge with one Br(1)Ba4Pb square pyramid, and  an edgeedge with one Se(5)Ba2GePb trigonal pyramid. The corner-sharing octahedral tilt angles are 44°. In the sixth Se site, Se(6) is bonded in a 4-coordinate geometry to one Ba(1), one Ba(2), one Pb(1), and one Ge(2) atom. There are two inequivalent Br sites. In the first Br site, Br(1) is bonded to four equivalent Ba(1) and one Pb(1) atom to form BrBa4Pb square pyramids that share  a cornercorner with one Se(2)Ba4GePb octahedra, corners with two equivalent Se(3)Ba4Ge square pyramids, corners with two equivalent Se(4)Ba4Ge square pyramids, corners with four equivalent Br(1)Ba4Pb square pyramids, corners with two equivalent Se(5)Ba2GePb trigonal pyramids,  an edgeedge with one Se(3)Ba4Ge square pyramid,  an edgeedge with one Se(4)Ba4Ge square pyramid, edges with four equivalent Se(1)Ba4Ge square pyramids, and edges with two equivalent Se(5)Ba2GePb trigonal pyramids. The corner-sharing octahedral tilt angles are 12°. In the second Br site, Br(2) is bonded in a rectangular see-saw-like geometry to four equivalent Ba(2) atoms.
Ba4Ge2PbSe8Br2 crystallizes in the orthorhombic Pmn2_1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one Se(3), one Se(4), one Se(5), one Se(6), two equivalent Se(1), and two equivalent Br(1) atoms. The Ba(1)-Se(3) bond length is 3.38 Å. The Ba(1)-Se(4) bond length is 3.37 Å. The Ba(1)-Se(5) bond length is 3.48 Å. The Ba(1)-Se(6) bond length is 3.50 Å. There is one shorter (3.43 Å) and one longer (3.60 Å) Ba(1)-Se(1) bond length. There is one shorter (3.45 Å) and one longer (3.54 Å) Ba(1)-Br(1) bond length. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to one Se(3), one Se(4), one Se(5), one Se(6), two equivalent Se(2), and two equivalent Br(2) atoms. The Ba(2)-Se(3) bond length is 3.45 Å. The Ba(2)-Se(4) bond length is 3.43 Å. The Ba(2)-Se(5) bond length is 3.68 Å. The Ba(2)-Se(6) bond length is 3.41 Å. There is one shorter (3.46 Å) and one longer (3.51 Å) Ba(2)-Se(2) bond length. There is one shorter (3.42 Å) and one longer (3.54 Å) Ba(2)-Br(2) bond length. Pb(1) is bonded to one Se(2), two equivalent Se(5), two equivalent Se(6), and one Br(1) atom to form distorted PbSe5Br octahedra that share corners with three equivalent Ge(2)Se4 tetrahedra and  an edgeedge with one Ge(1)Se4 tetrahedra. The Pb(1)-Se(2) bond length is 3.16 Å. Both Pb(1)-Se(5) bond lengths are 2.91 Å. Both Pb(1)-Se(6) bond lengths are 3.17 Å. The Pb(1)-Br(1) bond length is 3.08 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one Se(1), one Se(3), and two equivalent Se(5) atoms to form GeSe4 tetrahedra that share  an edgeedge with one Pb(1)Se5Br octahedra. The Ge(1)-Se(1) bond length is 2.38 Å. The Ge(1)-Se(3) bond length is 2.38 Å. Both Ge(1)-Se(5) bond lengths are 2.39 Å. In the second Ge site, Ge(2) is bonded to one Se(2), one Se(4), and two equivalent Se(6) atoms to form GeSe4 tetrahedra that share corners with three equivalent Pb(1)Se5Br octahedra. The corner-sharing octahedral tilt angles range from 5-16°. The Ge(2)-Se(2) bond length is 2.47 Å. The Ge(2)-Se(4) bond length is 2.39 Å. Both Ge(2)-Se(6) bond lengths are 2.34 Å. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded to four equivalent Ba(1) and one Ge(1) atom to form distorted SeBa4Ge square pyramids that share corners with two equivalent Se(3)Ba4Ge square pyramids, corners with two equivalent Se(4)Ba4Ge square pyramids, corners with four equivalent Se(1)Ba4Ge square pyramids, corners with two equivalent Se(5)Ba2GePb trigonal pyramids,  an edgeedge with one Se(4)Ba4Ge square pyramid, edges with four equivalent Br(1)Ba4Pb square pyramids, edges with two equivalent Se(5)Ba2GePb trigonal pyramids, and  a faceface with one Se(3)Ba4Ge square pyramid. In the second Se site, Se(2) is bonded to four equivalent Ba(2), one Pb(1), and one Ge(2) atom to form distorted SeBa4GePb octahedra that share corners with four equivalent Se(2)Ba4GePb octahedra,  a cornercorner with one Br(1)Ba4Pb square pyramid, corners with two equivalent Se(3)Ba4Ge square pyramids, corners with two equivalent Se(4)Ba4Ge square pyramids, corners with two equivalent Se(5)Ba2GePb trigonal pyramids,  an edgeedge with one Se(3)Ba4Ge square pyramid, edges with two equivalent Se(5)Ba2GePb trigonal pyramids, and  a faceface with one Se(4)Ba4Ge square pyramid. The corner-sharing octahedral tilt angles are 31°. In the third Se site, Se(3) is bonded to two equivalent Ba(1), two equivalent Ba(2), and one Ge(1) atom to form distorted SeBa4Ge square pyramids that share corners with two equivalent Se(2)Ba4GePb octahedra, corners with two equivalent Se(1)Ba4Ge square pyramids, corners with two equivalent Br(1)Ba4Pb square pyramids, corners with two equivalent Se(5)Ba2GePb trigonal pyramids,  an edgeedge with one Se(2)Ba4GePb octahedra,  an edgeedge with one Br(1)Ba4Pb square pyramid, edges with two equivalent Se(4)Ba4Ge square pyramids, edges with two equivalent Se(5)Ba2GePb trigonal pyramids, and  a faceface with one Se(1)Ba4Ge square pyramid. The corner-sharing octahedral tilt angles are 59°. In the fourth Se site, Se(4) is bonded to two equivalent Ba(1), two equivalent Ba(2), and one Ge(2) atom to form distorted SeBa4Ge square pyramids that share corners with two equivalent Se(2)Ba4GePb octahedra, corners with two equivalent Se(1)Ba4Ge square pyramids, corners with two equivalent Br(1)Ba4Pb square pyramids, corners with four equivalent Se(5)Ba2GePb trigonal pyramids,  an edgeedge with one Se(1)Ba4Ge square pyramid,  an edgeedge with one Br(1)Ba4Pb square pyramid, edges with two equivalent Se(3)Ba4Ge square pyramids, and  a faceface with one Se(2)Ba4GePb octahedra. The corner-sharing octahedral tilt angles are 43°. In the fifth Se site, Se(5) is bonded to one Ba(1), one Ba(2), one Pb(1), and one Ge(1) atom to form distorted SeBa2GePb trigonal pyramids that share  a cornercorner with one Se(2)Ba4GePb octahedra,  a cornercorner with one Se(1)Ba4Ge square pyramid,  a cornercorner with one Se(3)Ba4Ge square pyramid,  a cornercorner with one Br(1)Ba4Pb square pyramid, corners with two equivalent Se(4)Ba4Ge square pyramids,  an edgeedge with one Se(2)Ba4GePb octahedra,  an edgeedge with one Se(1)Ba4Ge square pyramid,  an edgeedge with one Se(3)Ba4Ge square pyramid,  an edgeedge with one Br(1)Ba4Pb square pyramid, and  an edgeedge with one Se(5)Ba2GePb trigonal pyramid. The corner-sharing octahedral tilt angles are 44°. In the sixth Se site, Se(6) is bonded in a 4-coordinate geometry to one Ba(1), one Ba(2), one Pb(1), and one Ge(2) atom. There are two inequivalent Br sites. In the first Br site, Br(1) is bonded to four equivalent Ba(1) and one Pb(1) atom to form BrBa4Pb square pyramids that share  a cornercorner with one Se(2)Ba4GePb octahedra, corners with two equivalent Se(3)Ba4Ge square pyramids, corners with two equivalent Se(4)Ba4Ge square pyramids, corners with four equivalent Br(1)Ba4Pb square pyramids, corners with two equivalent Se(5)Ba2GePb trigonal pyramids,  an edgeedge with one Se(3)Ba4Ge square pyramid,  an edgeedge with one Se(4)Ba4Ge square pyramid, edges with four equivalent Se(1)Ba4Ge square pyramids, and edges with two equivalent Se(5)Ba2GePb trigonal pyramids. The corner-sharing octahedral tilt angles are 12°. In the second Br site, Br(2) is bonded in a rectangular see-saw-like geometry to four equivalent Ba(2) atoms.