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.

Relative integrated intensities of the bands of theD¹Π →X¹Σ⁺ system of SnO have been measured by the technique of heterochromatic photographic photometry. Using the Rydberg-Klein-Rees Franck-Condon factors andr-centroids, the variation of electronic transition momentR_e with the internuclear separationr is found to beR_e(r)=const. (0.564r−1) in the range of 1.865 A≤r≤2.041A. The relative band strengths are derived. Effective vibrational temperature of the source is found to be 2559 K.

Relative intensities of a few bands of the B1→X¹Σ⁺ system of PbO have been measured by the technique of heterochromatic photographic photometry. The Franck-Condon factors andr-centroids have been computed by the more reliable numerical integration procedure, using a suitable potential. The effective vibrational temperature of the source is found to be 3836 K.