Nanotubular structures made of cystine-based cyclobisamides assembled by stacking through hydrogen bonding between amidic groups were recently synthesized. A quantum mechanical study at Hartree-Fock and DFT levels was performed on such monomers and dimers, and the obtained geometrical data were compared with the corresponding experimental values on the polymers. The electrostatic potential derived from the wave function seems to be a suitable tool for testing the ability to form hydrogen bonds and, as a consequence, for suggesting the synthesis of new nanotubes with different structural units providing efficient hydrogen-bonding stacking interactions.