Materials Data on Sr(CaSi3)2 by Materials Project

Abstract

Sr(CaSi3)2 is High Pressure (4-7GPa) Tellurium-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Sr is bonded to six Si atoms to form distorted SrSi6 octahedra that share edges with two equivalent SrSi6 octahedra and edges with four equivalent CaSi6 octahedra. All Sr–Si bond lengths are 3.13 Å. Ca is bonded to six Si atoms to form distorted CaSi6 octahedra that share edges with two equivalent SrSi6 octahedra and edges with four equivalent CaSi6 octahedra. There are a spread of Ca–Si bond distances ranging from 3.04–3.10 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded in a 6-coordinate geometry to two equivalent Sr, one Ca, and three Si atoms. There are two shorter (2.41 Å) and one longer (2.42 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 6-coordinate geometry to three equivalent Ca and three Si atoms. The Si–Si bond length is 2.40 Å. In the third Si site, Si is bonded in a 6-coordinate geometry to one Sr, two equivalent Ca, and three Si atoms. Both Si–Si bond lengths are 2.44 Å.