Studies on the analytical potential energy function of diatomic molecular ion XY+ using variational method

A new analytical potential energy function for diatomic molecular ion XY+ is proposed based on the energy consistent method (ECM). The Coulomb potential included in the new ionic potential contains multipole corrections, converges quickly and is variationally changeable. The new potential and the ECM are applied to variationally studying the potential energies of eight electronic states of several diatomic molecular ions: the A(2)Pi state of CO+, the X(2)Sigma(g)(+) state of Li-2(+), the X(2)Sigma(g)(+) state of He-2(+), the 1(2)Pi(u) state of Na-2,(+) the A(2)Pi(u) state of N-2,(+) the X(1)Sigma(+) state of KrH+, the X(2)Sigma(+) state of SiO+ and the A(2)Pi state of SO+ ion. The present results agree excellently with the experiment-based Rydberg-Klein-Rees (RKR) potentials, and are superior to the commonly used Huxley-Murrell-Sorbie (HMS) analytical potentials, and are better in some cases than some quantum mechanical ab initio potentials in the ionic asymptotic and dissociation regions.