DOE OSTI2020
BaCu2Te2(O3Cl)2 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to six O2- and two equivalent Cl1- atoms. There are a spread of Ba–O bond distances ranging from 2.62–3.06 Å. There are one shorter (3.09 Å) and one longer (3.22 Å) Ba–Cl bond lengths. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ 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 1.95–2.02 Å. In the second Cu2+ site, Cu2+ is bonded in a 6-coordinate geometry to three O2- and three Cl1- atoms. There are a spread of Cu–O bond distances ranging from 1.96–2.02 Å. There are a spread of Cu–Cl bond distances ranging from 2.32–3.16 Å. There are two inequivalent Te4+ sites. In the first Te4+ site, Te4+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Te–O bond distances ranging from 1.90–1.93 Å. In the second Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.93–2.36 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ba2+, one Cu2+, and one Te4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Cu2+, and one Te4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Cu2+ and two Te4+ atoms. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to two Cu2+ and one Te4+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, one Cu2+, and one Te4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+, one Cu2+, and one Te4+ atom. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted single-bond geometry to two equivalent Cu2+ atoms. In the second Cl1- site, Cl1- is bonded in a 3-coordinate geometry to two equivalent Ba2+ and one Cu2+ atom.