DOI: 10.17188/1283245
title: Materials Data on Na2UI6 by Materials Project

description: Na2UI6 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six I1- atoms to form NaI6 octahedra that share corners with four NaI6 octahedra, corners with six UI6 octahedra, and a faceface with one NaI6 octahedra. The corner-sharing octahedra tilt angles range from 41–59°. There are a spread of Na–I bond distances ranging from 3.24–3.30 Å. In the second Na1+ site, Na1+ is bonded to six I1- atoms to form NaI6 octahedra that share a cornercorner with one NaI6 octahedra, edges with three NaI6 octahedra, and edges with three UI6 octahedra. The corner-sharing octahedral tilt angles are 56°. There are a spread of Na–I bond distances ranging from 3.19–3.39 Å. In the third Na1+ site, Na1+ is bonded to six I1- atoms to form NaI6 octahedra that share corners with two equivalent NaI6 octahedra, an edgeedge with one NaI6 octahedra, edges with three UI6 octahedra, and a faceface with one NaI6 octahedra. The corner-sharing octahedra tilt angles range from 56–58°. There are a spread of Na–I bond distances ranging from 3.16–3.43 Å. In the fourth Na1+ site, Na1+ is bonded to six I1- atoms to form NaI6 octahedra that share edges with three NaI6 octahedra and edges with three UI6 octahedra. There are a spread of Na–I bond distances ranging from 3.18–3.41 Å. In the fifth Na1+ site, Na1+ is bonded to six I1- atoms to form NaI6 octahedra that share edges with three NaI6 octahedra and edges with three UI6 octahedra. There are a spread of Na–I bond distances ranging from 3.18–3.40 Å. In the sixth Na1+ site, Na1+ is bonded to six I1- atoms to form NaI6 octahedra that share a cornercorner with one NaI6 octahedra, edges with two equivalent NaI6 octahedra, and edges with three UI6 octahedra. The corner-sharing octahedral tilt angles are 59°. There are a spread of Na–I bond distances ranging from 3.18–3.41 Å. There are three inequivalent U4+ sites. In the first U4+ site, U4+ is bonded to six I1- atoms to form UI6 octahedra that share corners with three equivalent NaI6 octahedra and edges with four NaI6 octahedra. The corner-sharing octahedra tilt angles range from 41–43°. There are a spread of U–I bond distances ranging from 2.97–3.06 Å. In the second U4+ site, U4+ is bonded to six I1- atoms to form UI6 octahedra that share corners with three equivalent NaI6 octahedra and edges with five NaI6 octahedra. The corner-sharing octahedra tilt angles range from 41–42°. There are a spread of U–I bond distances ranging from 3.04–3.12 Å. In the third U4+ site, U4+ is bonded to six I1- atoms to form UI6 octahedra that share edges with six NaI6 octahedra. There are one shorter (3.03 Å) and five longer (3.04 Å) U–I bond lengths. There are eighteen inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted trigonal planar geometry to two Na1+ and one U4+ atom. In the second I1- site, I1- is bonded in a distorted trigonal planar geometry to two Na1+ and one U4+ atom. In the third I1- site, I1- is bonded in a distorted trigonal planar geometry to two Na1+ and one U4+ atom. In the fourth I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom. In the fifth I1- site, I1- is bonded in a rectangular see-saw-like geometry to three Na1+ and one U4+ atom. In the sixth I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom. In the seventh I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom. In the eighth I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom. In the ninth I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom. In the tenth I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom. In the eleventh I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom. In the twelfth I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom. In the thirteenth I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom. In the fourteenth I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom. In the fifteenth I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom. In the sixteenth I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom. In the seventeenth I1- site, I1- is bonded in an L-shaped geometry to one Na1+ and one U4+ atom. In the eighteenth I1- site, I1- is bonded in a distorted T-shaped geometry to two Na1+ and one U4+ atom.