Materials Data on CaU3Ti8O24 by Materials Project
CaU3Ti8O24 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with eight TiO6 octahedra and edges with two equivalent UO6 octahedra. The corner-sharing octahedra tilt angles range from 44–67°. There are a spread of Ca–O bond distances ranging from 2.31–2.40 Å. There are two inequivalent U+4.67+ sites. In the first U+4.67+ site, U+4.67+ is bonded to six O2- atoms to form UO6 octahedra that share corners with eight TiO6 octahedra, an edgeedge with one CaO6 octahedra, and an edgeedge with one UO6 octahedra. The corner-sharing octahedra tilt angles range from 37–62°. There are a spread of U–O bond distances ranging from 2.16–2.26 Å. In the second U+4.67+ site, U+4.67+ is bonded to six O2- atoms to form distorted UO6 octahedra that share corners with eight TiO6 octahedra and edges with two equivalent UO6 octahedra. The corner-sharing octahedra tilt angles range from 41–63°. There are two shorter (2.18 Å) and four longer (2.29 Å) U–O bond lengths. There are four inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share a cornercorner with one CaO6 octahedra, corners with two TiO6 octahedra, corners with three UO6 octahedra, and edges with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 28–63°. There are a spread of Ti–O bond distances ranging from 1.92–2.11 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share a cornercorner with one CaO6 octahedra, corners with two TiO6 octahedra, corners with three UO6 octahedra, and edges with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 27–67°. There are a spread of Ti–O bond distances ranging from 1.83–2.18 Å. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share a cornercorner with one CaO6 octahedra, corners with two TiO6 octahedra, corners with three UO6 octahedra, and edges with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 28–63°. There are a spread of Ti–O bond distances ranging from 1.81–2.15 Å. In the fourth Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share a cornercorner with one CaO6 octahedra, corners with two TiO6 octahedra, corners with three UO6 octahedra, and edges with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 27–66°. There are a spread of Ti–O bond distances ranging from 1.84–2.18 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three Ti4+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to three Ti4+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to three Ti4+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to three Ti4+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one U+4.67+ and two Ti4+ atoms. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one U+4.67+ and two Ti4+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Ti4+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one U+4.67+ and two Ti4+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two U+4.67+ and one Ti4+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ca2+, one U+4.67+, and one Ti4+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two U+4.67+ and one Ti4+ atom. In the twelfth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ca2+, one U+4.67+, and one Ti4+ atom.