Materials Data on CaU2(PO9)2 by Materials Project
(CaU2P2O17)2O2 crystallizes in the monoclinic Pm space group. The structure is three-dimensional and consists of one water molecule and one CaU2P2O17 framework. In the CaU2P2O17 framework, Ca is bonded in a 4-coordinate geometry to four O atoms. There are a spread of Ca–O bond distances ranging from 2.22–2.56 Å. There are two inequivalent U sites. In the first U site, U is bonded to six O atoms to form UO6 octahedra that share corners with four PO4 tetrahedra. There are a spread of U–O bond distances ranging from 1.91–2.51 Å. In the second U site, U is bonded to six O atoms to form UO6 octahedra that share corners with four PO4 tetrahedra. There are a spread of U–O bond distances ranging from 1.82–2.26 Å. There are two inequivalent P sites. In the first P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with four UO6 octahedra. The corner-sharing octahedra tilt angles range from 35–38°. There is two shorter (1.53 Å) and two longer (1.57 Å) P–O bond length. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with four UO6 octahedra. The corner-sharing octahedra tilt angles range from 34–39°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. There are thirteen inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to one U and one P atom. In the second O site, O is bonded in a bent 150 degrees geometry to one U and one P atom. In the third O site, O is bonded in a bent 150 degrees geometry to one U and one P atom. In the fourth O site, O is bonded in a distorted bent 150 degrees geometry to one U and one P atom. In the fifth O site, O is bonded in a bent 150 degrees geometry to one U and one P atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to one U and one P atom. In the seventh O site, O is bonded in a trigonal planar geometry to one U and two equivalent O atoms. Both O–O bond lengths are 1.40 Å. In the eighth O site, O is bonded in a single-bond geometry to one U atom. In the ninth O site, O is bonded in a linear geometry to one Ca and one U atom. In the tenth O site, O is bonded in a single-bond geometry to one U atom. In the eleventh O site, O is bonded in a distorted single-bond geometry to one Ca and two equivalent O atoms. Both O–O bond lengths are 1.46 Å. In the twelfth O site, O is bonded in an L-shaped geometry to one Ca and one O atom. In the thirteenth O site, O is bonded in a 1-coordinate geometry to two O atoms. The O–O bond length is 1.47 Å.