Materials Data on Na3Np(HO3)2 by Materials Project
Na3Np(HO3)2 crystallizes in the orthorhombic Fdd2 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with eight equivalent NaO4 tetrahedra and edges with three equivalent NpO6 octahedra. There are a spread of Na–O bond distances ranging from 2.36–2.53 Å. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with four equivalent NaO6 octahedra, corners with four equivalent NpO6 octahedra, and corners with two equivalent NaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–77°. There are a spread of Na–O bond distances ranging from 2.29–2.34 Å. Np7+ is bonded to six O2- atoms to form NpO6 octahedra that share corners with eight equivalent NaO4 tetrahedra and edges with three equivalent NaO6 octahedra. There are a spread of Np–O bond distances ranging from 1.93–2.24 Å. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to three Na1+ and one Np7+ atom to form corner-sharing ONa3Np tetrahedra. 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 distorted single-bond geometry to two Na1+, one Np7+, and one H1+ atom.