Pb3(SeO3)2Br2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent Br(1) atoms. In the second Pb site, Pb(2) is bonded in a 8-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and three equivalent Br(1) atoms. Se(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. There are three inequivalent O sites. In the first O site, O(2) is bonded in a 4-coordinate geometry to one Pb(1), two equivalent Pb(2), and one Se(1) atom. In the second O site, O(3) is bonded in a 1-coordinate geometry to one Pb(1), one Pb(2), and one Se(1) atom. In the third O site, O(1) is bonded to one Pb(1), two equivalent Pb(2), and one Se(1) atom to form distorted corner-sharing OPb3Se tetrahedra. Br(1) is bonded in a distorted see-saw-like geometry to one Pb(1) and three equivalent Pb(2) atoms.
Pb3(SeO3)2Br2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent Br(1) atoms. Both Pb(1)-O(1) bond lengths are 2.63 Å. Both Pb(1)-O(2) bond lengths are 2.78 Å. Both Pb(1)-O(3) bond lengths are 2.79 Å. Both Pb(1)-Br(1) bond lengths are 3.20 Å. In the second Pb site, Pb(2) is bonded in a 8-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and three equivalent Br(1) atoms. The Pb(2)-O(3) bond length is 2.65 Å. There is one shorter (2.53 Å) and one longer (2.60 Å) Pb(2)-O(1) bond length. There is one shorter (2.60 Å) and one longer (2.74 Å) Pb(2)-O(2) bond length. There are a spread of Pb(2)-Br(1) bond distances ranging from 3.15-3.37 Å. Se(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. The Se(1)-O(1) bond length is 1.78 Å. The Se(1)-O(2) bond length is 1.76 Å. The Se(1)-O(3) bond length is 1.69 Å. There are three inequivalent O sites. In the first O site, O(2) is bonded in a 4-coordinate geometry to one Pb(1), two equivalent Pb(2), and one Se(1) atom. In the second O site, O(3) is bonded in a 1-coordinate geometry to one Pb(1), one Pb(2), and one Se(1) atom. In the third O site, O(1) is bonded to one Pb(1), two equivalent Pb(2), and one Se(1) atom to form distorted corner-sharing OPb3Se tetrahedra. Br(1) is bonded in a distorted see-saw-like geometry to one Pb(1) and three equivalent Pb(2) atoms.