Materials Data on YCo9Si4 by Materials Project
YCo9Si4 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. Y3+ is bonded in a 8-coordinate geometry to eight equivalent Si4- atoms. All Y–Si bond lengths are 3.22 Å. There are three inequivalent Co+1.44+ sites. In the first Co+1.44+ site, Co+1.44+ is bonded in a 6-coordinate geometry to two equivalent Co+1.44+ and four equivalent Si4- atoms. Both Co–Co bond lengths are 2.30 Å. There are two shorter (2.47 Å) and two longer (2.53 Å) Co–Si bond lengths. In the second Co+1.44+ site, Co+1.44+ is bonded to four equivalent Si4- atoms to form a mixture of corner and edge-sharing CoSi4 tetrahedra. There are two shorter (2.29 Å) and two longer (2.42 Å) Co–Si bond lengths. In the third Co+1.44+ site, Co+1.44+ is bonded in a distorted square co-planar geometry to four equivalent Si4- atoms. All Co–Si bond lengths are 2.32 Å. Si4- is bonded in a 12-coordinate geometry to two equivalent Y3+ and nine Co+1.44+ atoms.