Materials Data on TlCu2(AsO4)2 by Materials Project
Cu2Tl(AsO4)2 crystallizes in the monoclinic P2_1/c 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 rectangular see-saw-like geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.88–1.99 Å. In the second Cu+1.50+ site, Cu+1.50+ is bonded to five O2- atoms to form distorted CuO5 trigonal bipyramids that share corners with five AsO4 tetrahedra. There are a spread of Cu–O bond distances ranging from 1.92–2.49 Å. Tl3+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Tl–O bond distances ranging from 2.58–2.77 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with three equivalent CuO5 trigonal bipyramids. There are a spread of As–O bond distances ranging from 1.71–1.78 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent CuO5 trigonal bipyramids. There are a spread of As–O bond distances ranging from 1.69–1.76 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to two Cu+1.50+ and one As5+ atom. In the second O2- site, O2- is bonded in a water-like geometry to one Cu+1.50+ and one As5+ atom. In the third O2- site, O2- is bonded in a water-like geometry to one Cu+1.50+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Cu+1.50+ and one As5+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Tl3+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cu+1.50+, one Tl3+, and one As5+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Cu+1.50+, one Tl3+, and one As5+ atom. In the eighth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu+1.50+ and one As5+ atom.