DOI: 10.17188/1729497
title: Materials Data on Na4NpH7O9 by Materials Project

description: Na4NpH7O9 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share a cornercorner with one NaO6 octahedra, edges with two equivalent NaO6 octahedra, and edges with three equivalent NpO6 octahedra. The corner-sharing octahedral tilt angles are 24°. There are a spread of Na–O bond distances ranging from 2.37–2.55 Å. In the second Na1+ site, Na1+ is bonded in a 7-coordinate geometry to one H1+ and six O2- atoms. The Na–H bond length is 2.53 Å. There are a spread of Na–O bond distances ranging from 2.36–2.58 Å. In the third Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share a cornercorner with one NaO6 octahedra, an edgeedge with one NaO6 octahedra, and edges with two equivalent NpO6 octahedra. The corner-sharing octahedral tilt angles are 24°. There are a spread of Na–O bond distances ranging from 2.35–2.52 Å. In the fourth Na1+ site, Na1+ is bonded in a 2-coordinate geometry to two H1+ and six O2- atoms. There are one shorter (2.39 Å) and one longer (2.61 Å) Na–H bond lengths. There are a spread of Na–O bond distances ranging from 2.32–2.93 Å. Np7+ is bonded to six O2- atoms to form NpO6 octahedra that share edges with five NaO6 octahedra. There are a spread of Np–O bond distances ranging from 1.91–2.36 Å. There are seven inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one Na1+ and one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one Na1+ and one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one Na1+ and one O2- atom. The H–O bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.57 Å) H–O bond length. In the fifth 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 sixth 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 seventh H1+ site, H1+ is bonded in a distorted single-bond geometry to one O2- atom. The H–O bond length is 1.02 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+ and one Np7+ atom. In the second O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Na1+ and one Np7+ atom. In the third O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one Np7+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+ and one Np7+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to three Na1+, one Np7+, and one H1+ atom. In the sixth O2- site, O2- is bonded in a single-bond geometry to four Na1+, one Np7+, and one H1+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Na1+ and two H1+ atoms. In the eighth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the ninth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms.