Materials Data on Ca5Si3 by Materials Project
Ca5Si3 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded to five Si atoms to form a mixture of distorted edge, face, and corner-sharing CaSi5 trigonal bipyramids. There are a spread of Ca–Si bond distances ranging from 3.05–3.24 Å. In the second Ca site, Ca is bonded in a square co-planar geometry to four equivalent Si atoms. All Ca–Si bond lengths are 3.08 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to eight Ca and one Si atom. The Si–Si bond length is 2.44 Å. In the second Si site, Si is bonded in a 8-coordinate geometry to eight equivalent Ca atoms.
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