DOE OSTI2020
K10Co4O9 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are ten inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a distorted trigonal planar geometry to three O2- atoms. There are a spread of K–O bond distances ranging from 2.69–2.87 Å. In the second K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.65–3.06 Å. In the third K1+ site, K1+ is bonded in a distorted trigonal pyramidal geometry to four O2- atoms. There are a spread of K–O bond distances ranging from 2.66–2.72 Å. In the fourth K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.67–3.10 Å. In the fifth K1+ site, K1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are two shorter (2.70 Å) and one longer (2.75 Å) K–O bond lengths. In the sixth 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 2.71–2.98 Å. In the seventh K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.70–2.90 Å. In the eighth K1+ site, K1+ is bonded in a 4-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.61–3.30 Å. In the ninth 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 2.74–2.87 Å. In the tenth 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 2.68–2.86 Å. There are four inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of Co–O bond distances ranging from 1.81–1.99 Å. In the second Co2+ site, Co2+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of Co–O bond distances ranging from 1.81–1.91 Å. In the third Co2+ site, Co2+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of Co–O bond distances ranging from 1.80–1.94 Å. In the fourth Co2+ site, Co2+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of Co–O bond distances ranging from 1.81–1.99 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to five K1+ and one Co2+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to three K1+ and two Co2+ atoms. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five K1+ and one Co2+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to five K1+ and one Co2+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to five K1+ and one Co2+ atom. In the sixth O2- site, O2- is bonded in a 6-coordinate geometry to five K1+ and one Co2+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to five K1+ and two Co2+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to four K1+ and two Co2+ atoms. In the ninth O2- site, O2- is bonded in a distorted octahedral geometry to five K1+ and one Co2+ atom.