Materials Data on NbTl2PO6 by Materials Project
NbTl2PO6 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share corners with two equivalent NbO6 octahedra and corners with three PO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Nb–O bond distances ranging from 1.81–2.29 Å. There are two inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded in a 1-coordinate geometry to nine O2- atoms. There are a spread of Tl–O bond distances ranging from 2.71–3.40 Å. In the second Tl1+ site, Tl1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Tl–O bond distances ranging from 2.73–3.32 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent NbO6 octahedra. The corner-sharing octahedral tilt angles are 44°. There is one shorter (1.52 Å) and three longer (1.57 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent NbO6 octahedra. The corner-sharing octahedral tilt angles are 54°. There is one shorter (1.55 Å) and three longer (1.56 Å) P–O bond length. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent NbO6 octahedra. The corner-sharing octahedral tilt angles are 44°. There is one shorter (1.53 Å) and three longer (1.57 Å) P–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Nb5+ and two Tl1+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Tl1+ and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Nb5+, three equivalent Tl1+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to three equivalent Tl1+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Nb5+ and four equivalent Tl1+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Nb5+, two equivalent Tl1+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to three equivalent Tl1+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Nb5+, two equivalent Tl1+, and one P5+ atom.