Stability of the chain structure in liquid KxTe1-x (x=0.0, 0.2, and 0.5): Ab initio molecular-dynamics simulations

The stability of local chain structures formed by Te atoms in liquid K_xTe_1-x mixtures (x=0.0, 0.2, and 0.5) is studied by ab initio molecular-dynamics simulations. It is confirmed by investigating the atomic and electronic structures that at x=0.2, the chain structure of Te is stabilized by the presence of K atoms compared with the pure liquid Te, and that, at the equiatomic concentration, most of the Te atoms form the Te^2-₂ dimers, as expected by the Zintl rule. From the time evolution of local atomic configurations, it is found that the Zintl Te^2-₂ dimers interact with each other, and the bond breaking and the rearrangement of dimers occur rather frequently.