Crystal
and electronic structure of the ternary monoclinic selenide
Tl2.59Sb8.41Se14 (TlSb3Se5)
Chem.
Met. Alloys 9 (2016)
11-20
https://doi.org/10.30970/cma9.0316
Ihor BARCHIY,
Anatoliy TATZKAR, Marian SABOV, Ewa ROŻYCKA-SOKOŁOWSKA,
Bernard MARCINIAK, Volodymyr PAVLYUK
The ternary selenide Tl2.59Sb8.41Se14
crystallizes with a monoclinic structure in space group P21/m where
the atoms are located on 2e sites
(site symmetry m). The structure of
the title compound is closely related to the strongly disordered structure of K2.5Sb8.5Se14.
The coordination polyhedra of the thallium atoms are trigonal prisms with additional selenium atoms centering
lateral faces. All the antimony atoms are coordinated by slightly deformed Se6
octahedra. Three types of polyhedron: octahedron, trigonal bipyramid and
tetrahedron, are observed for the selenium atoms. The crystal
chemical analysis and electronic structure calculations by the TB-LMTO-ASA method show that the antimony and selenium atoms
form a polyanionic network the negative charge of
which is compensated by the thallium cations.
Polyanionic 3D-network of
selenium and antimony atoms.
Keywords
Selenide / Crystal structure / Electronic
structure