Materials Data on Ho3Si13Ir4 by Materials Project

Abstract

Ho3Ir4Si13 crystallizes in the cubic Pm-3n space group. The structure is three-dimensional. Ho3+ is bonded to twelve equivalent Si+2.15- atoms to form distorted HoSi12 cuboctahedra that share corners with eight equivalent IrSi6 pentagonal pyramids, edges with eight equivalent HoSi12 cuboctahedra, faces with two equivalent HoSi12 cuboctahedra, faces with four equivalent SiSi12 cuboctahedra, and faces with four equivalent IrSi6 pentagonal pyramids. There are eight shorter (3.08 Å) and four longer (3.19 Å) Ho–Si bond lengths. Ir+4.75+ is bonded to six equivalent Si+2.15- atoms to form distorted IrSi6 pentagonal pyramids that share corners with six equivalent HoSi12 cuboctahedra, corners with six equivalent IrSi6 pentagonal pyramids, faces with two equivalent SiSi12 cuboctahedra, and faces with three equivalent HoSi12 cuboctahedra. All Ir–Si bond lengths are 2.43 Å. There are two inequivalent Si+2.15- sites. In the first Si+2.15- site, Si+2.15- is bonded in a 2-coordinate geometry to three equivalent Ho3+, two equivalent Ir+4.75+, and one Si+2.15- atom. The Si–Si bond length is 2.84 Å. In the second Si+2.15- site, Si+2.15- is bonded to twelve equivalent Si+2.15- atoms to form SiSi12 cuboctahedra that share faces with twelve equivalent HoSi12 cuboctahedra and faces with eight equivalent IrSi6 pentagonal pyramids.