DOE OSTI2020
KAlO2 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of K–O bond distances ranging from 2.72–2.83 Å. In the second 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 2.83–3.21 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. All Al–O bond lengths are 1.78 Å. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. There is one shorter (1.77 Å) and three longer (1.78 Å) Al–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to four K1+ and two equivalent Al3+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to three equivalent K1+ and two Al3+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two K1+ and two equivalent Al3+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to three K1+ and two Al3+ atoms.