Materials Data on La2Ir7 by Materials Project

Abstract

La2Ir7 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent La sites. In the first La site, La is bonded in a 12-coordinate geometry to twelve Ir atoms. There are a spread of La–Ir bond distances ranging from 3.11–3.46 Å. In the second La site, La is bonded in a 6-coordinate geometry to eighteen Ir atoms. There are a spread of La–Ir bond distances ranging from 3.12–3.56 Å. There are five inequivalent Ir sites. In the first Ir site, Ir is bonded in a 12-coordinate geometry to three equivalent La and six Ir atoms. There are three shorter (2.63 Å) and three longer (2.70 Å) Ir–Ir bond lengths. In the second Ir site, Ir is bonded to six equivalent La and six equivalent Ir atoms to form IrLa6Ir6 cuboctahedra that share corners with twelve equivalent IrLa5Ir7 cuboctahedra, edges with six equivalent IrLa6Ir6 cuboctahedra, and faces with eighteen equivalent IrLa5Ir7 cuboctahedra. All Ir–Ir bond lengths are 2.78 Å. In the third Ir site, Ir is bonded to four equivalent La and eight Ir atoms to form IrLa4Ir8 cuboctahedra that share corners with sixteen IrLa5Ir7 cuboctahedra, edges with ten IrLa5Ir7 cuboctahedra, and faces with ten IrLa4Ir8 cuboctahedra. There are four shorter (2.68 Å) and two longer (2.72 Å) Ir–Ir bond lengths. In the fourth Ir site, Ir is bonded to five La and seven Ir atoms to form distorted IrLa5Ir7 cuboctahedra that share corners with seventeen IrLa6Ir6 cuboctahedra, edges with eight IrLa4Ir8 cuboctahedra, and faces with fourteen IrLa6Ir6 cuboctahedra. There are a spread of Ir–Ir bond distances ranging from 2.65–2.72 Å. In the fifth Ir site, Ir is bonded in a 12-coordinate geometry to three equivalent La and six Ir atoms.