The ordering potential and concentration-concentration structure factor of a liquid Li-Na alloy

Ordering potentials of a liquid Li-Na alloy are obtained from pair interactions calculated by pseudopotential theory. They are compared with an experimentally based potential deduced from the neutron diffraction observations of Ruppersberg and Knoll (1977). The agreement is reasonably good for an appropriate parameter choice. The concentration-concentration structure factor is then calculated in the random-phase approximation, starting from the ab initio pair potentials, and comparison is made with the observed one. It is thus shown that certain characteristic features of the latter can, in some measure, be reproduced theoretically from first principles.