Materials Data on Np2SeO9 by Materials Project

Abstract

Np2SeO9 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Np7+ sites. In the first Np7+ site, Np7+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Np–O bond distances ranging from 1.85–2.55 Å. In the second Np7+ site, Np7+ is bonded to seven O2- atoms to form distorted NpO7 pentagonal bipyramids that share corners with three equivalent SeO4 tetrahedra. There are a spread of Np–O bond distances ranging from 1.83–2.48 Å. Se4+ is bonded to four O2- atoms to form SeO4 tetrahedra that share corners with three equivalent NpO7 pentagonal bipyramids. There is three shorter (1.67 Å) and one longer (1.70 Å) Se–O bond length. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two Np7+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Np7+ and one Se4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two Np7+ and one Se4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two Np7+ atoms. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two Np7+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to one Np7+ and one Se4+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one Np7+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to two Np7+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Np7+ and one Se4+ atom.