Materials Data on KNaSi2O5 by Materials Project

Abstract

NaKSi2O5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.80–3.11 Å. Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.29–2.70 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.59–1.67 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.58–1.68 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Si4+ atoms. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Na1+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, three equivalent Na1+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Na1+, and two Si4+ atoms.