Materials Data on Sc2CoSi2 by Materials Project
Sc2CoSi2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to six Si4- atoms to form distorted ScSi6 pentagonal pyramids that share corners with four equivalent ScSi6 pentagonal pyramids, corners with four equivalent CoSi4 tetrahedra, edges with six equivalent ScSi6 pentagonal pyramids, edges with two equivalent CoSi4 tetrahedra, and a faceface with one ScSi6 pentagonal pyramid. There are a spread of Sc–Si bond distances ranging from 2.70–2.92 Å. In the second Sc3+ site, Sc3+ is bonded in a 6-coordinate geometry to six Si4- atoms. There are a spread of Sc–Si bond distances ranging from 2.72–2.87 Å. Co2+ is bonded to four Si4- atoms to form CoSi4 tetrahedra that share corners with four equivalent ScSi6 pentagonal pyramids, corners with two equivalent CoSi4 tetrahedra, edges with two equivalent ScSi6 pentagonal pyramids, and edges with two equivalent CoSi4 tetrahedra. There are a spread of Co–Si bond distances ranging from 2.28–2.40 Å. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 9-coordinate geometry to seven Sc3+, one Co2+, and one Si4- atom. The Si–Si bond length is 2.48 Å. In the second Si4- site, Si4- is bonded in a 10-coordinate geometry to five Sc3+, three equivalent Co2+, and one Si4- atom. The Si–Si bond length is 2.51 Å.