Semiclassical theory of electronic states in multilayer semiconductors. Part 1

States of electrons in multilayer semiconductor structures are theoretically investigated in the semiclassical approximation, where one-electron wave functions of the stationary Schrödinger equation are calculated in the presence of various types of potential, which is a slowly varying function of the coordinate. It is determined that the energy spectrum of electrons in the potential in the quadratic approximation takes discrete values and the steepness of the energy spectrum depends on the parameters of the expansion of the potential in coordinates.