The valence‐bond model, so widely used in chemistry, is equally applicable to transition metal alloys. In contrast to models commonly used by physicists, this model emphasizes the distribution of electrons in real space and the differences in spatial distribution of f and d electrons in contrast to s and p electrons. From the energies of the different electronic configurations that are known for almost all of the gaseous atoms and bonding energies for different types of electrons, one can calculate the energies of the electronic configurations in the metal. Thus Ba, Ta, and W with gaseous ground states s2, d3s2, and d4s2are calculated to have the predominant configurations ds, d4s, and d5s, respectively, in the metal. The determination of the correct electronic configuration in the metal is the keystone to reliable predictions. The bonding energies due to the different types of electrons can be used to readily evaluate thermodynamic data to predict the stable composition range for a given structure, or the crystal structure that is stable at a given composition and temperature, and the effect of pressure, temperature and alloying upon the relative stabilities of different structures as well as the occurrence of magnetism.