Abstract
On the basis of the analysis of the optical absorption spectra and conductivity data the model of the electronic structure of the regular three-dimensional arrays of minimum-diameter (0.6 nm) quantum wires of Tl, Pb and Bi has been proposed. It is characterized by a dielectric type of energy spectrum, an atomic-like energy band structure near the gap, anisotropy of this spectrum and localization of the electronic states near the gap.