Abstract
The structure and chemical bonding properties of liquid K-Sb alloys have been investigated using neutron scattering experiments and ab initio molecular-dynamics simulations. For alloys containing between 25 and 50 at. % Sb, the neutron data demonstrate the existence of a well-defined prepeak at Q ∼ 1.15 Å reflecting a pronounced short-range order. The ab initio calculations show that the chemical bonding obeys a generalized Zintl principle, i.e. a formally complete electron transfer from K to Sb. The liquid structure is determined for the "octet" composition K3Sb by charge ordering effects leading to a salt-like atomic arrangement, at the equiatomic composition by the formation of short covalently bonded Sb chains in close analogy to the isoelectronic chalcogen elements in the liquid state.