Materials Data on KNO3 by Materials Project

Abstract

KNO3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. K1+ is bonded to seven O2- atoms to form a mixture of distorted edge and corner-sharing KO7 pentagonal bipyramids. There are a spread of K–O bond distances ranging from 2.76–2.91 Å. N5+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.27 Å) and one longer (1.28 Å) N–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three equivalent K1+ and one N5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+ and one N5+ atom.