The development of composition optimization methods of oxide, fluoride, and chalcogenide materials for interference coatings using the valence state of metal in complex compounds and composites is considered. It is shown that the electronegativity of elements plays an important role in the formation of substances of a certain composition in such systems. An explanation of CVD (chemical vapor deposition) used in film formation based on metal (oxide) chalcogenide-germanium composites is offered.