ALGEBRAIC DETERMINATION OF THE VIBRATIONAL QUANTUM NUMBERS OF A DIATOMIC MOLECULE

The quantum numbers of electronic-vibrational levels of a diatomic molecule are assigned using a new and simple algebraic procedure which is applied to data from a single absorption spectrum of the molecule. This procedure represents a considerable simplification in the solution to the problem of quantum numbering of a molecule since the method does not need additional spectra of other isotopic species, nor does it use advanced, yet more complicated, molecular potentials different from the usual Morse potential. In this paper the new method, applied to the absorption bands from the lowest X (1)SIGMA(g)+ state of I2 to the vibrational manifold of its B (3)PI(Ou)+ excited electronic state, allows the assignation of the quantum numbers of the vibrational levels and, in addition, the evaluation of the main spectroscopic constants with reasonable accuracy even when a low-resolution spectrum is used as the input data.