Materials Data on YU(CuSi)4 by Materials Project

Abstract

UY(CuSi)4 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. U6+ is bonded to eight equivalent Si4- atoms to form USi8 hexagonal bipyramids that share corners with sixteen equivalent CuSi4 tetrahedra, edges with four equivalent USi8 hexagonal bipyramids, edges with eight equivalent CuSi4 tetrahedra, and faces with four equivalent USi8 hexagonal bipyramids. All U–Si bond lengths are 3.04 Å. Y3+ is bonded in a distorted body-centered cubic geometry to eight equivalent Si4- atoms. All Y–Si bond lengths are 3.05 Å. Cu+1.75+ is bonded to four Si4- atoms to form CuSi4 tetrahedra that share corners with four equivalent USi8 hexagonal bipyramids, corners with four equivalent CuSi4 tetrahedra, edges with two equivalent USi8 hexagonal bipyramids, and edges with four equivalent CuSi4 tetrahedra. There are two shorter (2.37 Å) and two longer (2.40 Å) Cu–Si bond lengths. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 9-coordinate geometry to four equivalent U6+, four equivalent Cu+1.75+, and one Si4- atom. The Si–Si bond length is 2.32 Å. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to four equivalent Y3+, four equivalent Cu+1.75+, and one Si4- atom. The Si–Si bond length is 2.38 Å.