Materials Data on Np2SO9 by Materials Project

Np2SO9 crystallizes in the orthorhombic Pnma space group. The structure is two-dimensional and consists of two Np2SO9 sheets oriented in the (0, 0, 1) direction. there are two inequivalent Np6+ sites. In the first Np6+ site, Np6+ is bonded to seven O2- atoms to form distorted NpO7 pentagonal bipyramids that share corners with three equivalent SO4 tetrahedra. There are a spread of Np–O bond distances ranging from 1.83–2.42 Å. In the second Np6+ site, Np6+ is bonded in a 3-coordinate geometry to five O2- atoms. There are a spread of Np–O bond distances ranging from 1.84–2.46 Å. S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with three equivalent NpO7 pentagonal bipyramids. There are a spread of S–O bond distances ranging from 1.47–1.50 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Np6+ and one S6+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Np6+ and one S6+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two Np6+ atoms. In the fourth O2- site, O2- is bonded in a single-bond geometry to one Np6+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Np6+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Np6+ atoms. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to one Np6+ and one S6+ atom.