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.

The X-ray Debye-Waller factors and Debye temperatures of lead nitrate single crystals taken in the powder form have been determined by measuring integrated intensities of selected Bragg reflections at different temperatures. The characteristic specific Debye temperature has been compared with the value obtained from elastic constant data.