Materials Data on Ba4UCr2S9 by Materials Project

Abstract

Ba4UCr2S9 crystallizes in the trigonal P321 space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine S2- atoms. There are a spread of Ba–S bond distances ranging from 3.12–3.55 Å. In the second Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten S2- atoms. There are a spread of Ba–S bond distances ranging from 3.21–3.84 Å. In the third Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.14–3.34 Å. There are two inequivalent U4+ sites. In the first U4+ site, U4+ is bonded to six S2- atoms to form distorted US6 pentagonal pyramids that share faces with two CrS6 octahedra. There are three shorter (2.67 Å) and three longer (2.72 Å) U–S bond lengths. In the second U4+ site, U4+ is bonded to six equivalent S2- atoms to form distorted US6 pentagonal pyramids that share faces with two equivalent CrS6 octahedra. All U–S bond lengths are 2.69 Å. There are three inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to six S2- atoms to form CrS6 octahedra that share a faceface with one CrS6 octahedra and a faceface with one US6 pentagonal pyramid. All Cr–S bond lengths are 2.46 Å. In the second Cr3+ site, Cr3+ is bonded to six S2- atoms to form CrS6 octahedra that share a faceface with one CrS6 octahedra and a faceface with one US6 pentagonal pyramid. There are three shorter (2.41 Å) and three longer (2.45 Å) Cr–S bond lengths. In the third Cr3+ site, Cr3+ is bonded to six S2- atoms to form CrS6 octahedra that share a faceface with one CrS6 octahedra and a faceface with one US6 pentagonal pyramid. There are three shorter (2.42 Å) and three longer (2.46 Å) Cr–S bond lengths. There are five inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to four Ba2+, one U4+, and one Cr3+ atom. In the second S2- site, S2- is bonded to four Ba2+, one U4+, and one Cr3+ atom to form distorted SBa4UCr octahedra that share corners with eight SBa4UCr octahedra, an edgeedge with one SBa4Cr2 octahedra, and faces with five SBa4UCr octahedra. The corner-sharing octahedra tilt angles range from 2–63°. In the third S2- site, S2- is bonded in a 6-coordinate geometry to four Ba2+, one U4+, and one Cr3+ atom. In the fourth S2- site, S2- is bonded to four Ba2+ and two Cr3+ atoms to form distorted SBa4Cr2 octahedra that share corners with seven SBa4UCr octahedra, edges with two SBa4Cr2 octahedra, and faces with four SBa4UCr octahedra. The corner-sharing octahedra tilt angles range from 2–63°. In the fifth S2- site, S2- is bonded to four Ba2+ and two equivalent Cr3+ atoms to form distorted SBa4Cr2 octahedra that share corners with eight SBa4UCr octahedra, edges with two equivalent SBa4Cr2 octahedra, and faces with two equivalent SBa4Cr2 octahedra. The corner-sharing octahedra tilt angles range from 26–56°.