Materials Data on Y5(Si5Ir2)2 by Materials Project

Abstract

Y5(Ir2Si5)2 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. there are three inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded to twelve Si+3.20- atoms to form distorted YSi12 cuboctahedra that share corners with eight equivalent IrSi5 trigonal bipyramids, edges with eight equivalent YSi8 hexagonal bipyramids, faces with two equivalent YSi12 cuboctahedra, and faces with four equivalent IrSi5 trigonal bipyramids. There are eight shorter (2.93 Å) and four longer (3.27 Å) Y–Si bond lengths. In the second Y3+ site, Y3+ is bonded to eight Si+3.20- atoms to form distorted YSi8 hexagonal bipyramids that share corners with four equivalent IrSi5 trigonal bipyramids, edges with four equivalent YSi12 cuboctahedra, faces with two equivalent YSi8 hexagonal bipyramids, and faces with four equivalent IrSi5 trigonal bipyramids. There are a spread of Y–Si bond distances ranging from 2.91–3.04 Å. In the third Y3+ site, Y3+ is bonded in a distorted q4 geometry to ten Si+3.20- atoms. There are eight shorter (3.21 Å) and two longer (3.24 Å) Y–Si bond lengths. Ir+4.25+ is bonded to five Si+3.20- atoms to form distorted IrSi5 trigonal bipyramids that share corners with two equivalent YSi12 cuboctahedra, corners with two equivalent YSi8 hexagonal bipyramids, corners with five equivalent IrSi5 trigonal bipyramids, a faceface with one YSi12 cuboctahedra, and faces with two equivalent YSi8 hexagonal bipyramids. There are a spread of Ir–Si bond distances ranging from 2.40–2.50 Å. There are three inequivalent Si+3.20- sites. In the first Si+3.20- site, Si+3.20- is bonded in a 9-coordinate geometry to six Y3+, two equivalent Ir+4.25+, and one Si+3.20- atom. The Si–Si bond length is 2.37 Å. In the second Si+3.20- site, Si+3.20- is bonded in a 2-coordinate geometry to five Y3+, two equivalent Ir+4.25+, and one Si+3.20- atom. The Si–Si bond length is 2.44 Å. In the third Si+3.20- site, Si+3.20- is bonded in a 2-coordinate geometry to four Y3+, two equivalent Ir+4.25+, and two equivalent Si+3.20- atoms. Both Si–Si bond lengths are 2.82 Å.