  Self-associates of nucleic acid components (stacking trimers and tetramers of
the base pairs of nucleic acids) and short fragments of nucleic acids are
nanoparticles (linear sizes of these particles are more than 10 A. Modern
quantum-mechanical methods and softwares allow one to perform ab initio
calculations of the systems consisting of 150-200 atoms with enough large basis
sets (for example, 6-31G*). The aim of this work is to reveal the peculiarities
of molecular and electronic structures, as well as the energy features of
nanoparticles of nucleic acid components.
