DOE OSTI2020
K3AsO4 crystallizes in the orthorhombic Cccm space group. The structure is three-dimensional. there are six inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 4-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.53–3.11 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.58–2.72 Å. In the third 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 2.93–3.30 Å. In the fourth K1+ site, K1+ is bonded in a 2-coordinate geometry to two O2- atoms. There are one shorter (2.56 Å) and one longer (2.83 Å) K–O bond lengths. In the fifth K1+ site, K1+ is bonded in a distorted L-shaped geometry to two equivalent O2- atoms. Both K–O bond lengths are 2.65 Å. In the sixth 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 2.89–3.28 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of As–O bond distances ranging from 1.72–1.74 Å. In the second As5+ site, As5+ is bonded in a tetrahedral geometry to four O2- atoms. All As–O bond lengths are 1.73 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to five K1+ and one As5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three K1+ and one As5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three K1+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a 6-coordinate geometry to five K1+ and one As5+ atom. In the fifth O2- site, O2- is bonded in a 6-coordinate geometry to five K1+ and one As5+ atom.