Materials Data on ScU8S17 by Materials Project

Abstract

U8ScS17 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent U+3.88+ sites. In the first U+3.88+ site, U+3.88+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of U–S bond distances ranging from 2.72–2.82 Å. In the second U+3.88+ site, U+3.88+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of U–S bond distances ranging from 2.76–2.90 Å. In the third U+3.88+ site, U+3.88+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of U–S bond distances ranging from 2.67–3.00 Å. Sc3+ is bonded in an octahedral geometry to six S2- atoms. There are two shorter (2.45 Å) and four longer (2.52 Å) Sc–S bond lengths. There are seven inequivalent S2- sites. In the first S2- site, S2- is bonded to six U+3.88+ atoms to form a mixture of corner and face-sharing SU6 octahedra. In the second S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to four U+3.88+ atoms. In the third S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to four U+3.88+ atoms. In the fourth S2- site, S2- is bonded in a rectangular see-saw-like geometry to four U+3.88+ atoms. In the fifth S2- site, S2- is bonded to three U+3.88+ and one Sc3+ atom to form distorted SScU3 tetrahedra that share a cornercorner with one SU6 octahedra, corners with five equivalent SScU3 tetrahedra, a cornercorner with one SScU3 trigonal pyramid, edges with two equivalent SScU3 tetrahedra, and an edgeedge with one SScU3 trigonal pyramid. The corner-sharing octahedral tilt angles are 53°. In the sixth S2- site, S2- is bonded in a rectangular see-saw-like geometry to four U+3.88+ atoms. In the seventh S2- site, S2- is bonded to three U+3.88+ and one Sc3+ atom to form distorted SScU3 trigonal pyramids that share corners with two equivalent SScU3 tetrahedra, a cornercorner with one SScU3 trigonal pyramid, edges with two equivalent SScU3 tetrahedra, and a faceface with one SU6 octahedra.