Materials Data on Tb2CoSi2 by Materials Project

Abstract

Tb2CoSi2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Tb3+ sites. In the first Tb3+ site, Tb3+ is bonded in a 7-coordinate geometry to seven Si4- atoms. There are a spread of Tb–Si bond distances ranging from 2.88–3.26 Å. In the second Tb3+ site, Tb3+ is bonded to six Si4- atoms to form distorted TbSi6 pentagonal pyramids that share corners with four equivalent TbSi6 pentagonal pyramids, corners with four equivalent CoSi4 tetrahedra, edges with six equivalent TbSi6 pentagonal pyramids, edges with two equivalent CoSi4 tetrahedra, and a faceface with one TbSi6 pentagonal pyramid. There are a spread of Tb–Si bond distances ranging from 2.86–3.13 Å. Co2+ is bonded to four Si4- atoms to form CoSi4 tetrahedra that share corners with four equivalent TbSi6 pentagonal pyramids, corners with two equivalent CoSi4 tetrahedra, edges with two equivalent TbSi6 pentagonal pyramids, and edges with two equivalent CoSi4 tetrahedra. There are a spread of Co–Si bond distances ranging from 2.35–2.51 Å. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 10-coordinate geometry to six Tb3+, three equivalent Co2+, and one Si4- atom. The Si–Si bond length is 2.78 Å. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to seven Tb3+, one Co2+, and one Si4- atom. The Si–Si bond length is 2.57 Å.