Materials Data on KCo2As2HO8 by Materials Project
KCo2As2HO8 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 10-coordinate geometry to two equivalent H1+ and eight O2- atoms. Both K–H bond lengths are 2.86 Å. There are a spread of K–O bond distances ranging from 2.86–3.34 Å. In the second K1+ site, K1+ is bonded in a 12-coordinate geometry to two equivalent H1+ and ten O2- atoms. Both K–H bond lengths are 2.87 Å. There are a spread of K–O bond distances ranging from 2.83–3.43 Å. There are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six AsO4 tetrahedra and edges with three CoO6 octahedra. There are a spread of Co–O bond distances ranging from 2.05–2.19 Å. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six AsO4 tetrahedra and edges with three CoO6 octahedra. There are a spread of Co–O bond distances ranging from 2.04–2.16 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with six CoO6 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of As–O bond distances ranging from 1.70–1.75 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with six CoO6 octahedra. The corner-sharing octahedra tilt angles range from 55–59°. There are a spread of As–O bond distances ranging from 1.72–1.77 Å. H1+ is bonded in a distorted linear geometry to two K1+ and two O2- atoms. There is one shorter (1.03 Å) and one longer (1.58 Å) H–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, two equivalent Co2+, and one As5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Co2+ and one As5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one As5+, and one H1+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, two Co2+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, two equivalent Co2+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, two equivalent Co2+, and one As5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+, one As5+, and one H1+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, two equivalent Co2+, and one As5+ atom.