Materials Data on Ca5Si3O13 by Materials Project

Abstract

Ca5Si3O13 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of Ca–O bond distances ranging from 2.41–2.88 Å. In the second Ca site, Ca is bonded to seven O atoms to form distorted CaO7 pentagonal bipyramids that share corners with six equivalent CaO7 pentagonal bipyramids, corners with four equivalent SiO4 tetrahedra, and an edgeedge with one SiO4 tetrahedra. There are a spread of Ca–O bond distances ranging from 2.34–2.69 Å. Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four equivalent CaO7 pentagonal bipyramids and an edgeedge with one CaO7 pentagonal bipyramid. All Si–O bond lengths are 1.64 Å. There are four inequivalent O sites. In the first O site, O is bonded in a 1-coordinate geometry to three Ca and one Si atom. In the second O site, O is bonded in a trigonal planar geometry to three equivalent Ca atoms. In the third O site, O is bonded in a 1-coordinate geometry to three Ca and one Si atom. In the fourth O site, O is bonded to three Ca and one Si atom to form distorted edge-sharing OCa3Si tetrahedra.