Materials Data on TbCo9Si4 by Materials Project
TbCo9Si4 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. Tb3+ is bonded in a 8-coordinate geometry to eight equivalent Si4- atoms. All Tb–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 (2.45 Å) and two longer (2.52 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 edge and corner-sharing CoSi4 tetrahedra. There are a spread of Co–Si bond distances ranging from 2.28–2.42 Å. 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 2.30 Å. Si4- is bonded in a 12-coordinate geometry to two equivalent Tb3+, nine Co+1.44+, and one Si4- atom. The Si–Si bond length is 2.78 Å.