“…Meanwhile, for the analysis and estimations of the appropriate range of material parameters, spectral and optical characteristic of quantum dots at the first stage of investigation, conventionally, approximate eigenvalues and eigenfunctions evaluated in the analytical form were applied [6-8, 14, 22]. However, it is a real challenge to specify the range of applicability of such approximations in the problems, depending on a few parameters [2], e.g., for impurity states of quantum wires in a homogeneous magnetic field [25].…”