Materials Data on NaCaSiO4 by Materials Project
NaCaSiO4 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Na is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.32–2.81 Å. Ca is bonded to six O atoms to form CaO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with two equivalent CaO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.34–2.43 Å. Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with six equivalent CaO6 octahedra. The corner-sharing octahedra tilt angles range from 45–57°. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. There are three inequivalent O sites. In the first O site, O is bonded to one Na, two equivalent Ca, and one Si atom to form distorted corner-sharing ONaCa2Si tetrahedra. In the second O site, O is bonded in a 5-coordinate geometry to two equivalent Na, two equivalent Ca, and one Si atom. In the third O site, O is bonded in a 3-coordinate geometry to one Na, one Ca, and one Si atom.