Construction of potential curves for diatomic molecular states by the IPA method
Asen Pashov, Włodzimierz Jastrzębski, Paweł Kowalczyk Computer Physics Communications, 128(3), 622-634 (2000)
DOI: 10.1016/S0010-4655(00)00010-2
Software for calculation the transitions energies [cm-1] between state A and state B with example files: