For theB²Σ andX²Σ states of scandium monoxide, the potential energy curves are constructed by the Rydberg-Klein-Rees and the Morse methods. Morse model is shown to be adequate for the (B→X) band system of ScO. The r_e values are found to be 1.717 Å and 1.665 Å for theB andX states respectively.

Franck-Condon factors andr-centroids based on Rydberg-Klein-Rees potential have been computed for the CP (B²Σ⁺ —A²Π_i) band system. These results are compared with the Morse values and discussed.

The dissociation energies of the diatomic molecules BeCl, GaH and LiH have been computed by fitting empirical potential functions to the true potential energy curves for the electronic ground states of the molecules. The Lippincott three-parameter potential function, the five-parameter Hulburt-Hirschfelder potential function and the Szöke and Baitz electronegativity potential function have been used. The estimated dissociation energiesD₀⁰ are 4·50, 3·09 and 2·94 eV for BeCl, GaH and LiH respectively. These values compare well with the experimental values.