High-lying vibrational energies and analytical potential energy functions for some electronic states of diatomic ions

The full vibrational spectra especially those high-lying vibrational energies in the dissociation region of the electronic state A2Πu of N2+, the X2Πg state of F2+, the A2Πu and X2Πg states of O2+ are obtained using the variational algebraic method (VAM). Then, an analytical potential energy function (APEF) with adjustable parameter λ for each electronic state is determined by the 4-terms variational algebraic energy consistent method (VAECM(4)) based on the VAM vibrational energies. The full vibrational energies, the vibrational spectroscopic constants, the force constants fn, and the expansion coefficients an of the potential are tabulated. Compared with experimental and other calculated results, accurate APEFs, vibrational energy levels and spectroscopic parameters are obtained with the VAECM(4) for the four electronic states of diatomic ions. The results show that the VAECM(4) method also applies to diatomic ion systems.