The polyanions in liquid alkali-lead alloys - Ab initio molecular-dynamicssimulations

The ab-initio molecular-dynamics simulations are carried out for the liquid alkali(Li,Na,K)-Pb alloys to investigate the ionic structure, the electron ic states and especially the existence of the tetrahedral Pb-4(4-) polyanio ns, so-called 'Zintl-ions'. It is shown from our calculations that the Pb p olyanions become more stable with increasing size of the alkali atoms compo sing the liquid alloys, It is found that an ordering of the polyanions lead s to the first sharp diffraction peak of the observed structure factor.