and first-order enthalpy parameter 
in Cu–Au melts at 1550 K were calculated in terms of the lattice solution model and statistical theory of low-concentration melts.
The hi potential of the approach of two gold atoms in the face-centered cubic lattice of copper was used. The
theoretical parameter
= 3.2 was satisfactorily close to the experimental value 
= 3.7, whereas the the-oretical enthalpy parameter agreed with its experimental value only in sign and the order of magnitude.