Abstract The electron energy structure of titanium and hafnium carbide, titanium and solid solutions of TaC0.5N0.5 and Hf0.5Ta0.5C nitride is investigated experimentally (by X-ray and X-ray photoelectron spectroscopy) and theoretically (based on the quantum mechanical calculations in a full multiple scattering approximation, by the program FEFF8 with a self-consistent semirelativistic potential). A good accordance between the calculated curves of the densities of electronic states and the corresponding experimental curves is obtained. The chemical bond features in the investigated compounds and solutions are revealed.