Analytical interaction potentials of the long range alkali-metal dimers

Using almost degenerate perturbation theory the calculation of long range limits of alkali-metal dimer molecular states which dissociate to the atom pairs S-1/2-P-1/2, (3/2) and S-1/2-D-3/2,D- 5/2 is presented. Hund's coupling case c is adopted. The calculation includes correlations up to the second order of perturbation theory and exchange energy contributions. The results are expressed in a simple analytical form in terms of dispersion coefficients.