Materials Data on Sc2Cr4Si5 by Materials Project
Sc2Cr4Si5 crystallizes in the orthorhombic Ibam space group. The structure is three-dimensional. Sc2+ is bonded to seven Si+2.40- atoms to form a mixture of edge, corner, and face-sharing ScSi7 pentagonal bipyramids. There are a spread of Sc–Si bond distances ranging from 2.62–2.77 Å. There are two inequivalent Cr2+ sites. In the first Cr2+ site, Cr2+ is bonded in a 8-coordinate geometry to two equivalent Cr2+ and six Si+2.40- atoms. Both Cr–Cr bond lengths are 2.45 Å. There are two shorter (2.45 Å) and four longer (2.55 Å) Cr–Si bond lengths. In the second Cr2+ site, Cr2+ is bonded in a 7-coordinate geometry to seven Si+2.40- atoms. There are a spread of Cr–Si bond distances ranging from 2.39–2.76 Å. There are three inequivalent Si+2.40- sites. In the first Si+2.40- site, Si+2.40- is bonded in a 10-coordinate geometry to four equivalent Sc2+, four equivalent Cr2+, and two equivalent Si+2.40- atoms. Both Si–Si bond lengths are 2.45 Å. In the second Si+2.40- site, Si+2.40- is bonded in a 9-coordinate geometry to four equivalent Sc2+ and five Cr2+ atoms. In the third Si+2.40- site, Si+2.40- is bonded in a 10-coordinate geometry to one Sc2+, six Cr2+, and three equivalent Si+2.40- atoms. There are one shorter (2.37 Å) and two longer (2.71 Å) Si–Si bond lengths.