Li3Ge3Se6: the first ternary lithium germanium selenide with interesting ∞[Ge6Se12]n chains constructed by ethane-like [Ge2Se6]6− clusters

Abstract

Li₃Ge₃Se₆, the first compound of the ternary Li/Ge/Se system, has been synthesized. Note that interesting 1D _∞[Ge₆Se₁₂]_n chains constructed by ethane-like [Ge₂Se₆]⁶⁻ clusters were discovered in its structure. Investigations on the structures of all the [Ge₂Se₆]⁶⁻ cluster-containing compounds have shown that only in Li₃Ge₃Se₆ are there 1D chains composed of [Ge₂Se₆]⁶⁻ clusters, which result from the space limitation within the tunnels surrounded by LiSe₆ octahedra. Raman spectrum was obtained to demonstrate the existence of Ge–Ge bonds. UV-visible-NIR diffuse reflection spectrum showed an optical bandgap of 2.08 eV. Theoretical calculations based on first principles have also been performed for its band structure and density of states to analyze its structure–property relationship.