Materials Data on KSi2HO5 by Materials Project

Abstract

KHSi2O5 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to eight O2- atoms to form distorted KO8 hexagonal bipyramids that share corners with four equivalent SiO4 tetrahedra and edges with four equivalent SiO4 tetrahedra. There are four shorter (2.86 Å) and four longer (3.06 Å) K–O bond lengths. In the second K1+ site, K1+ is bonded to eight O2- atoms to form distorted KO8 hexagonal bipyramids that share corners with four equivalent SiO4 tetrahedra and edges with four equivalent SiO4 tetrahedra. There are four shorter (2.94 Å) and four longer (3.08 Å) K–O bond lengths. In the third K1+ site, K1+ is bonded in a 6-coordinate geometry to two equivalent O2- atoms. Both K–O bond lengths are 2.73 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one KO8 hexagonal bipyramid, corners with three SiO4 tetrahedra, and an edgeedge with one KO8 hexagonal bipyramid. There are a spread of Si–O bond distances ranging from 1.59–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one KO8 hexagonal bipyramid, corners with three SiO4 tetrahedra, and an edgeedge with one KO8 hexagonal bipyramid. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.10 Å) and one longer (1.36 Å) H–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+, one Si4+, and one H1+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one Si4+, and one H1+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms.