Materials Data on Na2CaSi by Materials Project
NaSiNaCa is alpha bismuth trifluoride-derived structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional and consists of four sodium molecules and one SiNaCa framework. In the SiNaCa framework, Na1+ is bonded to four equivalent Si4- atoms to form NaSi4 tetrahedra that share corners with four equivalent CaSi4 tetrahedra, corners with twelve equivalent NaSi4 tetrahedra, and edges with six equivalent CaSi4 tetrahedra. All Na–Si bond lengths are 3.18 Å. Ca2+ is bonded to four equivalent Si4- atoms to form CaSi4 tetrahedra that share corners with four equivalent NaSi4 tetrahedra, corners with twelve equivalent CaSi4 tetrahedra, and edges with six equivalent NaSi4 tetrahedra. All Ca–Si bond lengths are 3.18 Å. Si4- is bonded in a body-centered cubic geometry to four equivalent Na1+ and four equivalent Ca2+ atoms.