UPb(SeO4)2 crystallizes in the orthorhombic Pmc2_1 space group. U(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(9) atom to form distorted UO7 pentagonal bipyramids that share corners with two equivalent Pb(1)O5 square pyramids. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded to one O(8), two equivalent O(5), and two equivalent O(9) atoms to form distorted PbO5 square pyramids that share corners with four equivalent U(1)O7 pentagonal bipyramids. In the second Pb site, Pb(2) is bonded in a 5-coordinate geometry to one O(7), two equivalent O(4), and two equivalent O(6) atoms. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(7) and two equivalent O(1) atoms. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(3), one O(6), and one O(9) atom. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one O(8) and two equivalent O(2) atoms. There are nine inequivalent O sites. In the first O site, O(7) is bonded in a bent 120 degrees geometry to one Pb(2) and one Se(1) atom. In the second O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Pb(1) and one Se(3) atom. In the third O site, O(9) is bonded in a distorted trigonal planar geometry to one U(1), one Pb(1), and one Se(2) atom. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one U(1) and one Se(1) atom. In the fifth O site, O(2) is bonded in a bent 150 degrees geometry to one U(1) and one Se(3) atom. In the sixth O site, O(3) is bonded in a bent 150 degrees geometry to one U(1) and one Se(2) atom. In the seventh O site, O(4) is bonded in a single-bond geometry to one U(1) and one Pb(2) atom. In the eighth O site, O(5) is bonded in a distorted single-bond geometry to one U(1) and one Pb(1) atom. In the ninth O site, O(6) is bonded in a distorted trigonal planar geometry to one U(1), one Pb(2), and one Se(2) atom.
UPb(SeO4)2 crystallizes in the orthorhombic Pmc2_1 space group. U(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(9) atom to form distorted UO7 pentagonal bipyramids that share corners with two equivalent Pb(1)O5 square pyramids. The U(1)-O(1) bond length is 2.25 Å. The U(1)-O(2) bond length is 2.34 Å. The U(1)-O(3) bond length is 2.28 Å. The U(1)-O(4) bond length is 1.84 Å. The U(1)-O(5) bond length is 1.84 Å. The U(1)-O(6) bond length is 2.52 Å. The U(1)-O(9) bond length is 2.48 Å. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded to one O(8), two equivalent O(5), and two equivalent O(9) atoms to form distorted PbO5 square pyramids that share corners with four equivalent U(1)O7 pentagonal bipyramids. The Pb(1)-O(8) bond length is 2.44 Å. Both Pb(1)-O(5) bond lengths are 2.70 Å. Both Pb(1)-O(9) bond lengths are 2.42 Å. In the second Pb site, Pb(2) is bonded in a 5-coordinate geometry to one O(7), two equivalent O(4), and two equivalent O(6) atoms. The Pb(2)-O(7) bond length is 2.36 Å. Both Pb(2)-O(4) bond lengths are 2.70 Å. Both Pb(2)-O(6) bond lengths are 2.48 Å. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(7) and two equivalent O(1) atoms. The Se(1)-O(7) bond length is 1.70 Å. Both Se(1)-O(1) bond lengths are 1.74 Å. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(3), one O(6), and one O(9) atom. The Se(2)-O(3) bond length is 1.72 Å. The Se(2)-O(6) bond length is 1.75 Å. The Se(2)-O(9) bond length is 1.76 Å. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one O(8) and two equivalent O(2) atoms. The Se(3)-O(8) bond length is 1.70 Å. Both Se(3)-O(2) bond lengths are 1.76 Å. There are nine inequivalent O sites. In the first O site, O(7) is bonded in a bent 120 degrees geometry to one Pb(2) and one Se(1) atom. In the second O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Pb(1) and one Se(3) atom. In the third O site, O(9) is bonded in a distorted trigonal planar geometry to one U(1), one Pb(1), and one Se(2) atom. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one U(1) and one Se(1) atom. In the fifth O site, O(2) is bonded in a bent 150 degrees geometry to one U(1) and one Se(3) atom. In the sixth O site, O(3) is bonded in a bent 150 degrees geometry to one U(1) and one Se(2) atom. In the seventh O site, O(4) is bonded in a single-bond geometry to one U(1) and one Pb(2) atom. In the eighth O site, O(5) is bonded in a distorted single-bond geometry to one U(1) and one Pb(1) atom. In the ninth O site, O(6) is bonded in a distorted trigonal planar geometry to one U(1), one Pb(2), and one Se(2) atom.