Materials Data on TiP2O9 by Materials Project
TiP2O9 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of two TiP2O9 sheets oriented in the (0, 0, 1) direction. Ti is bonded to six O atoms to form TiO6 octahedra that share corners with three equivalent PO4 tetrahedra and corners with three equivalent PO4 trigonal pyramids. There are a spread of Ti–O bond distances ranging from 1.85–2.12 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 three equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 19–35°. There are a spread of P–O bond distances ranging from 1.50–1.57 Å. In the second P site, P is bonded to four O atoms to form PO4 trigonal pyramids that share corners with three equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 26–44°. There are a spread of P–O bond distances ranging from 1.50–1.94 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to one Ti and one P atom. In the second O site, O is bonded in a distorted bent 150 degrees geometry to one Ti and one P atom. In the third O site, O is bonded in a bent 120 degrees geometry to one P and one O atom. The O–O bond length is 1.27 Å. In the fourth O site, O is bonded in a bent 150 degrees geometry to one Ti and one P atom. In the fifth O site, O is bonded in a single-bond geometry to one O atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Ti and one P atom. In the seventh O site, O is bonded in a bent 150 degrees geometry to one Ti and one P atom. In the eighth O site, O is bonded in a single-bond geometry to one P atom. In the ninth O site, O is bonded in a bent 150 degrees geometry to one Ti and one P atom.