A valence-electron only model potential (V ALMOP) pseudopotential method has been developed utilising the GAUSSIAN 76 integral packages. VALMOP and the reference ab initio potential energy curves have been calculated for the ground electronic state of Li2, Na2 and NaLi using a number of different basis sets. Comparisons indicate that V ALMOP accurately reproduces internuclear bondlengths, valence orbital eigenvalues and, moreover, the shape of the all-electron potential energy curves over a large range of bondlength R.