DOE OSTI2020
Co3Cd(PO3)8 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. 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 PO4 tetrahedra, an edgeedge with one CoO6 octahedra, and an edgeedge with one CdO6 octahedra. There are a spread of Co–O bond distances ranging from 2.04–2.16 Å. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six PO4 tetrahedra and edges with two equivalent CoO6 octahedra. There are a spread of Co–O bond distances ranging from 2.05–2.25 Å. Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with six PO4 tetrahedra and edges with two equivalent CoO6 octahedra. There are a spread of Cd–O bond distances ranging from 2.20–2.34 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CdO6 octahedra, corners with two equivalent CoO6 octahedra, and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 19–57°. There are a spread of P–O bond distances ranging from 1.48–1.62 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three CoO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 21–59°. There are a spread of P–O bond distances ranging from 1.48–1.62 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CdO6 octahedra, corners with two CoO6 octahedra, and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 31–56°. There are a spread of P–O bond distances ranging from 1.48–1.62 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CdO6 octahedra, corners with two CoO6 octahedra, and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 27–58°. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two P5+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two P5+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Co2+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Co2+, one Cd2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Co2+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Co2+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cd2+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Co2+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Co2+, one Cd2+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to two Co2+ and one P5+ atom.