Potential energy curves, dissociation energies and Franck–Condon factors of NI and ScI molecules

The potential energy curves for the electronic ground states of NI and ScI molecules are constructed by using the RKRV method. The ground state dissociation energies of NI and ScI are determined by curve fitting techniques using the five parameters Hulburt–Hirschfelder function. The estimated dissociation energies are 1.64 and 2.85 eV for NI and ScI, respectively. The estimated dissociation energy values are in good agreement with the literature values. The Franck–Condon factors for the bands b 1 Σ +–X 3 Σ − system of NI and B 1 Π–X 1 Σ + system of ScI molecules have been determined using an approximate analytical method of Fraser and Jarmain. The absence of the bands in these systems is explained.