Dispersion interaction between the hydrogen atom and hydrogen like ions

The two-body dispersion interactions between the multipole of the hydrogen atom and the multipole of the hydrogen like ions and between multipoles of two hydrogen like ions have been worked out. The frequency dependent multipole polarizabilities have been worked out by the variational analog to the differential equation obtained from the hydrodynamic model analogy to quantum mechanics. Also, the [2, 1] Pade' approximants are used to construct the frequency dependent multipole polarizabilities from the multipole Cauchy's coefficients. The dispersion energy coefficients which appear in the expressions for the interaction energies of the H-He +, H-Li++, He+-He +, Li++-Li++ and He+-Li++ systems have been obtained up to the term R-10.