Abstract The traditional crystal packing study based on the analysis of geometrical characteristics of intermolecular interactions is found to be not informative enough. The application of quantum-chemical calculations for the evaluation of pairwise interaction energies between molecules allows to get much more information about supramolecular architecture. The staking interactions between π-systems of neighboring molecules form the building unit of the crystal packing in the absence of any strong interactions as well as in the presence of the N–H…O classical hydrogen bond. Unexpectedly the hydrogen bonds play the secondary role in the crystal packing formation as compared to stacking. Analysis of the total interaction energy of the basic molecule with all the molecules of its first coordination sphere and the pairwise interaction energies allows to evaluate the extent of crystal isotropy from point of view of interaction energies.