NpAgSeO5 crystallizes in the monoclinic P2_1/c space group. Np(1) is bonded in a 2-coordinate geometry to one O(2), one O(4), two equivalent O(1), and two equivalent O(5) atoms. Ag(1) is bonded in a 7-coordinate geometry to one O(1), one O(5), two equivalent O(2), and three equivalent O(4) atoms. Se(1) is bonded in a 3-coordinate geometry to one O(1), one O(3), and one O(5) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Np(1), one Ag(1), and one Se(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Np(1) and two equivalent Ag(1) atoms. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Se(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one Np(1) and three equivalent Ag(1) atoms. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Np(1), one Ag(1), and one Se(1) atom.
NpAgSeO5 crystallizes in the monoclinic P2_1/c space group. Np(1) is bonded in a 2-coordinate geometry to one O(2), one O(4), two equivalent O(1), and two equivalent O(5) atoms. The Np(1)-O(2) bond length is 1.88 Å. The Np(1)-O(4) bond length is 1.88 Å. There is one shorter (2.45 Å) and one longer (2.53 Å) Np(1)-O(1) bond length. There is one shorter (2.44 Å) and one longer (2.53 Å) Np(1)-O(5) bond length. Ag(1) is bonded in a 7-coordinate geometry to one O(1), one O(5), two equivalent O(2), and three equivalent O(4) atoms. The Ag(1)-O(1) bond length is 2.82 Å. The Ag(1)-O(5) bond length is 2.84 Å. There is one shorter (2.56 Å) and one longer (2.62 Å) Ag(1)-O(2) bond length. There are a spread of Ag(1)-O(4) bond distances ranging from 2.33-2.82 Å. Se(1) is bonded in a 3-coordinate geometry to one O(1), one O(3), and one O(5) atom. The Se(1)-O(1) bond length is 1.75 Å. The Se(1)-O(3) bond length is 1.72 Å. The Se(1)-O(5) bond length is 1.74 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Np(1), one Ag(1), and one Se(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Np(1) and two equivalent Ag(1) atoms. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Se(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to one Np(1) and three equivalent Ag(1) atoms. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Np(1), one Ag(1), and one Se(1) atom.