DOE OSTI2020
UHg3(TeCl3)2 is Krennerite-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. U4+ is bonded to six Cl1- atoms to form UCl6 octahedra that share corners with twelve HgTe2Cl4 octahedra. The corner-sharing octahedra tilt angles range from 41–66°. There are two shorter (2.62 Å) and four longer (2.64 Å) U–Cl bond lengths. There are two inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded to two equivalent Te2- and four Cl1- atoms to form HgTe2Cl4 octahedra that share corners with four equivalent UCl6 octahedra and edges with four HgTe2Cl4 octahedra. The corner-sharing octahedra tilt angles range from 41–66°. Both Hg–Te bond lengths are 2.72 Å. There are a spread of Hg–Cl bond distances ranging from 3.25–3.42 Å. In the second Hg2+ site, Hg2+ is bonded to two equivalent Te2- and four Cl1- atoms to form HgTe2Cl4 octahedra that share corners with four equivalent UCl6 octahedra and edges with four equivalent HgTe2Cl4 octahedra. The corner-sharing octahedra tilt angles range from 46–49°. Both Hg–Te bond lengths are 2.73 Å. There are two shorter (3.18 Å) and two longer (3.23 Å) Hg–Cl bond lengths. Te2- is bonded in a 5-coordinate geometry to three Hg2+ and two Cl1- atoms. There are one shorter (3.85 Å) and one longer (3.92 Å) Te–Cl bond lengths. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 1-coordinate geometry to one U4+ and two Hg2+ atoms. In the second Cl1- site, Cl1- is bonded in a distorted single-bond geometry to one U4+, two equivalent Hg2+, and one Te2- atom. In the third Cl1- site, Cl1- is bonded in a 1-coordinate geometry to one U4+, two Hg2+, and one Te2- atom.