Materials Data on KNaSO4 by Materials Project

Abstract

KNaSO4 crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 1-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.59–3.05 Å. In the second K1+ site, K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share edges with six equivalent KO12 cuboctahedra, edges with six SO4 tetrahedra, faces with three equivalent NaO7 hexagonal pyramids, and faces with two equivalent NaO6 octahedra. There are a spread of K–O bond distances ranging from 2.89–3.30 Å. There are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six SO4 tetrahedra, edges with three equivalent NaO7 hexagonal pyramids, and faces with two equivalent KO12 cuboctahedra. There are three shorter (2.36 Å) and three longer (2.37 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded to seven O2- atoms to form distorted NaO7 hexagonal pyramids that share corners with six equivalent NaO7 hexagonal pyramids, a cornercorner with one SO4 tetrahedra, edges with three equivalent NaO6 octahedra, edges with three equivalent SO4 tetrahedra, and faces with three equivalent KO12 cuboctahedra. There are one shorter (2.38 Å) and six longer (2.86 Å) Na–O bond lengths. There are two inequivalent S6+ sites. In the first S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with three equivalent NaO6 octahedra, edges with three equivalent KO12 cuboctahedra, and edges with three equivalent NaO7 hexagonal pyramids. The corner-sharing octahedral tilt angles are 17°. There is one shorter (1.47 Å) and three longer (1.50 Å) S–O bond length. In the second S6+ site, S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share a cornercorner with one NaO7 hexagonal pyramid, corners with three equivalent NaO6 octahedra, and edges with three equivalent KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 17°. There is one shorter (1.48 Å) and three longer (1.50 Å) S–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, three Na1+, and one S6+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three K1+, one Na1+, and one S6+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to four K1+ and one S6+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to three equivalent K1+, one Na1+, and one S6+ atom.