DOI: 10.17188/1712235
title: Materials Data on Na3NpH2Se2O11 by Materials Project

description: Na3NpH2Se2O11 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.35–3.04 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share a cornercorner with one NaO7 pentagonal bipyramid, a cornercorner with one NpO7 pentagonal bipyramid, corners with four SeO4 tetrahedra, an edgeedge with one NaO6 octahedra, an edgeedge with one NpO7 pentagonal bipyramid, and edges with two equivalent NaO7 pentagonal bipyramids. There are a spread of Na–O bond distances ranging from 2.38–2.66 Å. In the third Na1+ site, Na1+ is bonded to seven O2- atoms to form distorted NaO7 pentagonal bipyramids that share a cornercorner with one NaO6 octahedra, a cornercorner with one SeO4 tetrahedra, edges with two equivalent NaO6 octahedra, an edgeedge with one NaO7 pentagonal bipyramid, edges with two equivalent NpO7 pentagonal bipyramids, and edges with two equivalent SeO4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. There are a spread of Na–O bond distances ranging from 2.47–2.70 Å. Np7+ is bonded to seven O2- atoms to form distorted NpO7 pentagonal bipyramids that share a cornercorner with one NaO6 octahedra, corners with four SeO4 tetrahedra, an edgeedge with one NaO6 octahedra, and edges with two equivalent NaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 53°. There are a spread of Np–O bond distances ranging from 1.84–2.61 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are two inequivalent Se5+ sites. In the first Se5+ site, Se5+ is bonded to four O2- atoms to form SeO4 tetrahedra that share corners with three equivalent NaO6 octahedra, corners with two equivalent NpO7 pentagonal bipyramids, and edges with two equivalent NaO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 45–56°. There are a spread of Se–O bond distances ranging from 1.67–1.69 Å. In the second Se5+ site, Se5+ is bonded to four O2- atoms to form SeO4 tetrahedra that share a cornercorner with one NaO6 octahedra, a cornercorner with one NaO7 pentagonal bipyramid, and corners with two equivalent NpO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 60°. There are a spread of Se–O bond distances ranging from 1.66–1.69 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+ and one Se5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, one Np7+, and one Se5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Np7+, and one Se5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one Np7+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one Np7+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one Se5+ atom. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, one Np7+, and one Se5+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Na1+ and one Se5+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Np7+, and one Se5+ atom. In the tenth O2- site, O2- is bonded in a water-like geometry to one Na1+, one Np7+, and two H1+ atoms. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one Se5+ atom.