Np2SO9 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded to one O(1), one O(2), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form distorted NpO7 pentagonal bipyramids that share corners with three equivalent S(1)O4 tetrahedra. In the second Np site, Np(2) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(6), one O(7), and two equivalent O(3) atoms. S(1) is bonded to one O(4), one O(6), and two equivalent O(5) atoms to form SO4 tetrahedra that share corners with three equivalent Np(1)O7 pentagonal bipyramids. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a distorted single-bond geometry to one Np(1) and one S(1) atom. In the second O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Np(2) and one S(1) atom. In the third O site, O(1) is bonded in a distorted single-bond geometry to one Np(1) and one Np(2) atom. In the fourth O site, O(7) is bonded in a single-bond geometry to one Np(2) atom. In the fifth O site, O(2) is bonded in a distorted linear geometry to one Np(1) and one Np(2) atom. In the sixth O site, O(3) is bonded in a bent 120 degrees geometry to one Np(1) and one Np(2) atom. In the seventh O site, O(4) is bonded in a distorted single-bond geometry to one Np(1) and one S(1) atom.
Np2SO9 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded to one O(1), one O(2), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form distorted NpO7 pentagonal bipyramids that share corners with three equivalent S(1)O4 tetrahedra. The Np(1)-O(1) bond length is 1.81 Å. The Np(1)-O(2) bond length is 1.80 Å. The Np(1)-O(4) bond length is 2.45 Å. Both Np(1)-O(3) bond lengths are 2.21 Å. Both Np(1)-O(5) bond lengths are 2.41 Å. In the second Np site, Np(2) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(6), one O(7), and two equivalent O(3) atoms. The Np(2)-O(1) bond length is 2.48 Å. The Np(2)-O(2) bond length is 2.42 Å. The Np(2)-O(6) bond length is 2.38 Å. The Np(2)-O(7) bond length is 1.82 Å. Both Np(2)-O(3) bond lengths are 1.94 Å. S(1) is bonded to one O(4), one O(6), and two equivalent O(5) atoms to form SO4 tetrahedra that share corners with three equivalent Np(1)O7 pentagonal bipyramids. The S(1)-O(4) bond length is 1.46 Å. The S(1)-O(6) bond length is 1.46 Å. Both S(1)-O(5) bond lengths are 1.48 Å. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a distorted single-bond geometry to one Np(1) and one S(1) atom. In the second O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Np(2) and one S(1) atom. In the third O site, O(1) is bonded in a distorted single-bond geometry to one Np(1) and one Np(2) atom. In the fourth O site, O(7) is bonded in a single-bond geometry to one Np(2) atom. In the fifth O site, O(2) is bonded in a distorted linear geometry to one Np(1) and one Np(2) atom. In the sixth O site, O(3) is bonded in a bent 120 degrees geometry to one Np(1) and one Np(2) atom. In the seventh O site, O(4) is bonded in a distorted single-bond geometry to one Np(1) and one S(1) atom.