Molecular constants for the 1Σ+ ground state of the ArH+ ion

From the near equilibrium PNO-CEPA potential and dipole moment curves the following molecular constants for the ¹⁺ ground state of the ArH⁺ ion have been calculated: r_e = 1.286Å, _e = 2723 cm^–1, _ee = 56 cm^–1, D₀ = 3.89 eV and ₀ = 2.384 D. The rotationless radiative lifetimes of the five lowest vibrational states are predicted to be 2.28, 1.2, 0.85, 0.64, 0.46 for ArH⁺ and 9.09, 4.71, 3.27, 2.55 and 2.11 for ArD⁺, respectively (all values are in milliseconds and in ascending order of the vibrational levels).Dedicated to Prof. Hermann Hartmann on the occasion of his 65th birthday.