Bandgap (Forbidden Zone) is the basic parameter of the condensed matter, which characterizes a nature of chemical bonds and accordingly determines the chemical, physical-chemical and physical properties of solids. The type of the chemical bonds of compound, the stability of compounds in the certain interval of changes of composition and external parameters, the type of electronic conductivity, the possibility of ionic conductivity in samples, and also the basic thermodynamic characteristics of bonding in solids.
The database "Bandgap" covers values of width of forbidden zone of the major classes of inorganic substances. The database contains information on methods of bandgap determination and the appropriate temperature ranges. The data on chemical and phase composition of materials, type of a crystal lattice (crystal system, structural type, space group), orientations of samples at optical measurements are given in addition. The all data are provided with references. Database includes the extensive graphical information about dependences of bandgap on various factors.