Materials Data on KAlSiO4 by Materials Project

Abstract

KAlSiO4 crystallizes in the trigonal P3 space group. The structure is three-dimensional. K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 3.03–3.40 Å. Al3+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All Al–O bond lengths are 1.69 Å. Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There is one shorter (1.59 Å) and three longer (1.67 Å) Si–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent K1+, one Al3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent K1+ and one Si4+ atom.