Metal-semiconductor transition in liquid-alkali-Te mixtures: ab initio molecular-dynamics simulations

The structural and electronic properties of liquid RbxTe1-x mixtures (x = 0 .0, 0.2, and 0.5) are studied by ab initio molecular-dynamics simulations. It is shown that the transition from the metallic to the semiconducting sta te induced by adding Rb atoms is reproduced, and that this transition is re lated to the structural change in the Te chain. It is also shown from the c alculated electronic density of states that almost complete charge transfer from Rb to Te occurs in the mixtures. The correlation between the spatial distribution of the transferred charge in the Te chains and the positions o f Rb+ ions is investigated.