Materials Data on TlCu2P2O7 by Materials Project
Cu2TlP2O7 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. there are two inequivalent Cu+1.50+ sites. In the first Cu+1.50+ site, Cu+1.50+ is bonded in a distorted T-shaped geometry to one Tl1+ and three O2- atoms. The Cu–Tl bond length is 3.24 Å. There are two shorter (1.85 Å) and one longer (2.57 Å) Cu–O bond lengths. In the second Cu+1.50+ site, Cu+1.50+ is bonded to five O2- atoms to form CuO5 square pyramids that share corners with five PO4 tetrahedra. There are a spread of Cu–O bond distances ranging from 1.97–2.59 Å. Tl1+ is bonded in a 3-coordinate geometry to one Cu+1.50+ and nine O2- atoms. There are a spread of Tl–O bond distances ranging from 2.76–3.57 Å. There are two 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 CuO5 square pyramids and a cornercorner with one PO4 tetrahedra. There is three shorter (1.54 Å) and one longer (1.63 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 two equivalent CuO5 square pyramids and a cornercorner with one PO4 tetrahedra. There is three shorter (1.54 Å) and one longer (1.62 Å) P–O bond length. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two Cu+1.50+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu+1.50+, two equivalent Tl1+, and one P5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Cu+1.50+, one Tl1+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Tl1+ and two P5+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Cu+1.50+, one Tl1+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cu+1.50+, three equivalent Tl1+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Cu+1.50+, one Tl1+, and one P5+ atom.