Basicity of glass is still a challenge in spite of various attempts to measure or calculate it. The values assigned for basicity of glasses, either calculated or experimentally determined, are not always in full agreement with actual facts, and discrepancies among the theoretical ones are not unusual. For instance, SiO2 is described by a single basicity value even if the polymorphs of SiO2 are quite different. Only few attempts were made to face this challenge. This paper deals with a novel approach on theoretical ionicity/basicity based on electronic energy levels or band structure of solids. Considering the distribution of the interbonding angles specific for vitreous systems, it is possible to estimate both a local ionicity (basicity) of bondings and a global (mean) basicity of glass.
