Materials Data on Ca10Si6F by Materials Project
Ca10Si6F crystallizes in the tetragonal I-42m space group. The structure is three-dimensional. there are three inequivalent Ca sites. In the first Ca site, Ca is bonded in a single-bond geometry to five Si and one F atom. There are two shorter (3.12 Å) and three longer (3.21 Å) Ca–Si bond lengths. The Ca–F bond length is 2.35 Å. In the second Ca site, Ca is bonded to five Si atoms to form a mixture of distorted edge and corner-sharing CaSi5 trigonal bipyramids. There are a spread of Ca–Si bond distances ranging from 3.07–3.23 Å. In the third Ca site, Ca is bonded in a rectangular see-saw-like 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 8-coordinate geometry to eight Ca atoms. In the second Si site, Si is bonded in a 9-coordinate geometry to eight Ca and one Si atom. The Si–Si bond length is 2.42 Å. F is bonded in a tetrahedral geometry to four equivalent Ca atoms.