Materials Data on Sc3Fe2Si3 by Materials Project
Sc3Fe2Si3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Sc+2.67+ sites. In the first Sc+2.67+ site, Sc+2.67+ is bonded to five Si4- atoms to form ScSi5 trigonal bipyramids that share corners with four equivalent FeSi4 tetrahedra, corners with six equivalent ScSi5 trigonal bipyramids, and edges with four equivalent FeSi4 tetrahedra. There are a spread of Sc–Si bond distances ranging from 2.71–3.08 Å. In the second Sc+2.67+ site, Sc+2.67+ is bonded in a 6-coordinate geometry to seven Si4- atoms. There are a spread of Sc–Si bond distances ranging from 2.80–3.14 Å. Fe2+ is bonded to four Si4- atoms to form FeSi4 tetrahedra that share corners with three equivalent FeSi4 tetrahedra, corners with two equivalent ScSi5 trigonal bipyramids, edges with two equivalent FeSi4 tetrahedra, and edges with two equivalent ScSi5 trigonal bipyramids. There are a spread of Fe–Si bond distances ranging from 2.26–2.44 Å. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 9-coordinate geometry to seven Sc+2.67+ and two equivalent Fe2+ atoms. In the second Si4- site, Si4- is bonded in a 10-coordinate geometry to six Sc+2.67+, three equivalent Fe2+, and one Si4- atom. The Si–Si bond length is 2.55 Å.