Quantum chemical calculations have been performed on the various proton-bound rare gas dimers (RgHRg′)⁺ where Rg=Ar, Kr or Xe. A good agreement is obtained with respect to the experimental data for the antisymmetric stretching wavenumbers of the three RgHRg⁺ cations. For the mixed (RgHRg′)⁺ cations the computational results disagree with the recent experimental assignments (T. D. Fridgen and J. M. Parnis, J. Chem. Phys., 1998, 109, 2155) and a reassignment based on solvation of the centrosymmetric cations KrHKr⁺ and XeHXe⁺ is proposed.