Materials Data on U4N7 by Materials Project
U4N7 crystallizes in the orthorhombic Iba2 space group. The structure is three-dimensional. there are five inequivalent U+5.25+ sites. In the first U+5.25+ site, U+5.25+ is bonded to seven N3- atoms to form distorted UN7 pentagonal bipyramids that share a cornercorner with one UN6 octahedra, corners with two UN7 pentagonal bipyramids, an edgeedge with one UN6 octahedra, and edges with six UN7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 59°. There are a spread of U–N bond distances ranging from 2.20–2.39 Å. In the second U+5.25+ site, U+5.25+ is bonded to seven N3- atoms to form distorted UN7 pentagonal bipyramids that share a cornercorner with one UN6 octahedra, corners with two UN7 pentagonal bipyramids, an edgeedge with one UN6 octahedra, and edges with six UN7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 54°. There are a spread of U–N bond distances ranging from 2.20–2.43 Å. In the third U+5.25+ site, U+5.25+ is bonded to seven N3- atoms to form distorted UN7 pentagonal bipyramids that share a cornercorner with one UN6 octahedra, corners with two UN7 pentagonal bipyramids, an edgeedge with one UN6 octahedra, and edges with six UN7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 59°. There are a spread of U–N bond distances ranging from 2.20–2.39 Å. In the fourth U+5.25+ site, U+5.25+ is bonded to six N3- atoms to form a mixture of distorted edge and corner-sharing UN6 octahedra. There are a spread of U–N bond distances ranging from 2.22–2.24 Å. In the fifth U+5.25+ site, U+5.25+ is bonded in a body-centered cubic geometry to eight N3- atoms. There are a spread of U–N bond distances ranging from 2.28–2.44 Å. There are seven inequivalent N3- sites. In the first N3- site, N3- is bonded to four U+5.25+ atoms to form a mixture of distorted edge and corner-sharing NU4 tetrahedra. In the second N3- site, N3- is bonded to four U+5.25+ atoms to form a mixture of edge and corner-sharing NU4 tetrahedra. In the third N3- site, N3- is bonded to four U+5.25+ atoms to form a mixture of edge and corner-sharing NU4 tetrahedra. In the fourth N3- site, N3- is bonded to four U+5.25+ atoms to form a mixture of edge and corner-sharing NU4 tetrahedra. In the fifth N3- site, N3- is bonded to four U+5.25+ atoms to form a mixture of edge and corner-sharing NU4 tetrahedra. In the sixth N3- site, N3- is bonded to four U+5.25+ atoms to form a mixture of distorted edge and corner-sharing NU4 tetrahedra. In the seventh N3- site, N3- is bonded to four U+5.25+ atoms to form a mixture of edge and corner-sharing NU4 tetrahedra.