Materials Data on La6Si7Br3 by Materials Project
La6Si7Br3 crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. there are four inequivalent La+2.50+ sites. In the first La+2.50+ site, La+2.50+ is bonded in a 8-coordinate geometry to six Si+1.71- and two equivalent Br1- atoms. There are four shorter (3.14 Å) and two longer (3.16 Å) La–Si bond lengths. Both La–Br bond lengths are 3.20 Å. In the second La+2.50+ site, La+2.50+ is bonded in a 1-coordinate geometry to eight Si+1.71- and one Br1- atom. There are a spread of La–Si bond distances ranging from 3.13–3.22 Å. The La–Br bond length is 3.15 Å. In the third La+2.50+ site, La+2.50+ is bonded in a 8-coordinate geometry to four Si+1.71- and four Br1- atoms. There are two shorter (3.07 Å) and two longer (3.08 Å) La–Si bond lengths. There are a spread of La–Br bond distances ranging from 3.15–3.22 Å. In the fourth La+2.50+ site, La+2.50+ is bonded to twelve Si+1.71- atoms to form face-sharing LaSi12 cuboctahedra. There are a spread of La–Si bond distances ranging from 3.18–3.24 Å. There are four inequivalent Si+1.71- sites. In the first Si+1.71- site, Si+1.71- is bonded in a 8-coordinate geometry to six La+2.50+ and two equivalent Si+1.71- atoms. Both Si–Si bond lengths are 2.43 Å. In the second Si+1.71- site, Si+1.71- is bonded in a 8-coordinate geometry to six La+2.50+ and two equivalent Si+1.71- atoms. Both Si–Si bond lengths are 2.44 Å. In the third Si+1.71- site, Si+1.71- is bonded in a 8-coordinate geometry to six La+2.50+ and two Si+1.71- atoms. The Si–Si bond length is 2.43 Å. In the fourth Si+1.71- site, Si+1.71- is bonded in a 9-coordinate geometry to six La+2.50+ and three Si+1.71- atoms. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded to four La+2.50+ atoms to form a mixture of distorted corner and edge-sharing BrLa4 tetrahedra. In the second Br1- site, Br1- is bonded in a 4-coordinate geometry to four La+2.50+ atoms.