Materials Data on U5Re5Si9 by Materials Project
U5Re5Si9 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. there are four inequivalent U+4.20+ sites. In the first U+4.20+ site, U+4.20+ is bonded in a 9-coordinate geometry to nine Si4- atoms. There are six shorter (2.88 Å) and three longer (2.97 Å) U–Si bond lengths. In the second U+4.20+ site, U+4.20+ is bonded in a 9-coordinate geometry to nine Si4- atoms. There are a spread of U–Si bond distances ranging from 2.86–3.02 Å. In the third U+4.20+ site, U+4.20+ is bonded in a 9-coordinate geometry to nine Si4- atoms. There are a spread of U–Si bond distances ranging from 2.91–3.19 Å. In the fourth U+4.20+ site, U+4.20+ is bonded in a 4-coordinate geometry to four equivalent Si4- atoms. There are two shorter (2.94 Å) and two longer (2.98 Å) U–Si bond lengths. There are four inequivalent Re3+ sites. In the first Re3+ site, Re3+ is bonded in a distorted hexagonal planar geometry to six Si4- atoms. There are a spread of Re–Si bond distances ranging from 2.51–2.70 Å. In the second Re3+ site, Re3+ is bonded in a 6-coordinate geometry to six equivalent Si4- atoms. All Re–Si bond lengths are 2.70 Å. In the third Re3+ site, Re3+ is bonded to six Si4- atoms to form a mixture of distorted corner and face-sharing ReSi6 octahedra. There are a spread of Re–Si bond distances ranging from 2.42–2.52 Å. In the fourth Re3+ site, Re3+ is bonded to five Si4- atoms to form ReSi5 square pyramids that share corners with two equivalent ReSi6 octahedra, corners with four equivalent ReSi5 square pyramids, and a faceface with one ReSi6 octahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Re–Si bond distances ranging from 2.48–2.52 Å. There are four inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 9-coordinate geometry to four U+4.20+, three Re3+, and two equivalent Si4- atoms. Both Si–Si bond lengths are 2.55 Å. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to three U+4.20+, four Re3+, and two equivalent Si4- atoms. Both Si–Si bond lengths are 2.68 Å. In the third Si4- site, Si4- is bonded in a 9-coordinate geometry to five U+4.20+, three Re3+, and one Si4- atom. The Si–Si bond length is 2.50 Å. In the fourth Si4- site, Si4- is bonded in a 10-coordinate geometry to four U+4.20+, three Re3+, and three Si4- atoms. The Si–Si bond length is 2.47 Å.