Thermochemical properties of the rare earth monoxides

Abstract
Crystal field theory has been used to identify and locate the energy levels of low‐lying (below 10 000 cm1) states of the rare earth monoxides. These states were then used to calculate the thermal functions, which were, in turn, used to derive accurate dissociation energies of the rare earth monoxides. These newly derived dissociation energies are discussed in terms of a model related to the promotion energies for 4f n+15d0→4f n5d1.