Materials Data on K3Cr4PO16 by Materials Project
K3Cr4PO16 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are three 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 2.68–3.16 Å. In the second K1+ site, K1+ is bonded in a 1-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.77–3.33 Å. In the third 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 2.76–3.27 Å. There are four inequivalent Cr6+ sites. In the first Cr6+ site, Cr6+ is bonded to four O2- atoms to form CrO4 tetrahedra that share a cornercorner with one PO4 tetrahedra. There is three shorter (1.63 Å) and one longer (1.84 Å) Cr–O bond length. In the second Cr6+ site, Cr6+ is bonded to four O2- atoms to form CrO4 tetrahedra that share a cornercorner with one PO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.62–1.87 Å. In the third Cr6+ site, Cr6+ is bonded to four O2- atoms to form CrO4 tetrahedra that share a cornercorner with one PO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.62–1.85 Å. In the fourth Cr6+ site, Cr6+ is bonded to four O2- atoms to form CrO4 tetrahedra that share a cornercorner with one PO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 1.62–1.85 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four CrO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.53–1.55 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to two K1+ and one Cr6+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to three K1+ and one Cr6+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one Cr6+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to three K1+ and one Cr6+ atom. In the fifth O2- site, O2- is bonded in a distorted linear geometry to one K1+ and one Cr6+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one Cr6+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Cr6+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one Cr6+ atom. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one Cr6+ atom. In the tenth O2- site, O2- is bonded in a single-bond geometry to three K1+ and one Cr6+ atom. In the eleventh O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one Cr6+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr6+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one Cr6+ atom. In the fourteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr6+ and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one Cr6+ atom. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Cr6+, and one P5+ atom.