Materials Data on K3Na(SeO4)2 by Materials Project

Abstract

K3Na(SeO4)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.82–3.23 Å. In the second K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.65–3.29 Å. Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six equivalent SeO4 tetrahedra. There are four shorter (2.42 Å) and two longer (2.48 Å) Na–O bond lengths. Se6+ is bonded to four O2- atoms to form SeO4 tetrahedra that share corners with three equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 6–39°. There are a spread of Se–O bond distances ranging from 1.66–1.69 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to four K1+, one Na1+, and one Se6+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two K1+ and one Se6+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to four K1+, one Na1+, and one Se6+ atom. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to three K1+, one Na1+, and one Se6+ atom.