Second anion coordination for wurtzite and sphalerite chalcogenide derivatives as a tool for the description of anion sub-lattice

► A new method of the relationship of the structure of chalcogenides is proposed. ► The relation of the second coordination surrounding and the closest packing is shown. ► The second coordination sphere may be formed by single anions or by larger groupings. ► The use of this approach in the quantum-chemical calculations is proposed.