Pb2N2SeO9 crystallizes in the orthorhombic Pmn2_1 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(2), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms. In the second Pb site, Pb(2) is bonded in a 3-coordinate geometry to one O(1) and two equivalent O(2) atoms. There are two inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one O(3) and two equivalent O(4) atoms. In the second N site, N(2) is bonded in a trigonal planar geometry to one O(5) and two equivalent O(6) atoms. Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1) and two equivalent O(2) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Pb(2) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Pb(1), one Pb(2), and one Se(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to two equivalent Pb(1) and one N(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one Pb(1) and one N(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one N(2) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one Pb(1) and one N(2) atom.
Pb2N2SeO9 crystallizes in the orthorhombic Pmn2_1 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(2), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms. Both Pb(1)-O(2) bond lengths are 2.50 Å. Both Pb(1)-O(3) bond lengths are 2.82 Å. Both Pb(1)-O(4) bond lengths are 2.79 Å. Both Pb(1)-O(6) bond lengths are 2.68 Å. In the second Pb site, Pb(2) is bonded in a 3-coordinate geometry to one O(1) and two equivalent O(2) atoms. The Pb(2)-O(1) bond length is 2.41 Å. Both Pb(2)-O(2) bond lengths are 2.42 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one O(3) and two equivalent O(4) atoms. The N(1)-O(3) bond length is 1.26 Å. Both N(1)-O(4) bond lengths are 1.26 Å. In the second N site, N(2) is bonded in a trigonal planar geometry to one O(5) and two equivalent O(6) atoms. The N(2)-O(5) bond length is 1.25 Å. Both N(2)-O(6) bond lengths are 1.27 Å. Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1) and two equivalent O(2) atoms. The Se(1)-O(1) bond length is 1.71 Å. Both Se(1)-O(2) bond lengths are 1.72 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Pb(2) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Pb(1), one Pb(2), and one Se(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to two equivalent Pb(1) and one N(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one Pb(1) and one N(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one N(2) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one Pb(1) and one N(2) atom.