DFT (VASP) and semi-empirical (HyperChem) calculations for the L- and D-chiral diphenylalanine (L-FF and D-FF) nanotube (PNT) structures, empty and filled with water/ice clusters, are presented and analyzed. The results obtained show that after optimization, the dipole moment and polarization of both chiral type L-FF and D-FF PNT and embedded water/ice cluster are enhanced; the water/ice cluster acquire the helix-like structure similar as L-FF and D-FF PNT. Ferroelectric properties of tubular water/ice helix-like-cluster obtained after optimization inside L-FF and D-FF PNT and total L-FF and D-FF PNT with embedded water/ice cluster are discussed.
Keywords: Chirality; DFT; Diphenylalanine; Molecular modeling; Peptide nanotube; Polarization; Self-assembly; Semi-empirical methods; Water molecules.