Materials Data on K3Na(SO4)2 by Materials Project

Abstract

K3Na(SO4)2 crystallizes in the trigonal P-3m1 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 2.64–3.11 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 equivalent SO4 tetrahedra, and faces with two equivalent NaO6 octahedra. There are six shorter (2.95 Å) and six longer (3.34 Å) K–O bond lengths. Na1+ is bonded to six equivalent O2- atoms to form NaO6 octahedra that share corners with six equivalent SO4 tetrahedra and faces with two equivalent KO12 cuboctahedra. All Na–O bond lengths are 2.41 Å. S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share 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 (1.47 Å) and three longer (1.50 Å) S–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to four K1+, one Na1+, and one S6+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to four K1+ and one S6+ atom.