NEW ADVANCES IN THE STUDY OF LOCAL-STRUCTURE OF MOLTEN BINARY SALTS

Accurate extended x-ray absorption fine structure measurements of molt en RbBr and CuBr are analyzed and compared with computer simulations a nd neutron diffraction results. Advanced multiple-edge ab initio metho ds are used for data analysis. The short-range cation-anion pair distr ibution function of liquid RbBr is found to be in agreement with previ ous molecular dynamic simulations confirming the accuracy of present t heoretical models. In liquid CuBr, due to the exceptional short-range, sensitivity, direct evidence for nearly covalent bonding is obtained, improving previous neutron diffraction determinations. Possible impor tant consequences of present results for experimental studies of binar y liquid systems are addressed.