Quantum chemical study of non-covalent bonding in gentiodelphin

Low energy geometries of the diacylated anthocyanin gentiodelphin were characterized by means of computational chemistry methods. Using dispersion-corrected density functional theory (DFT-D), we have identified several geometries of gentiodelphin with similar energy, in majority closed structures with both acyl groups in near face-to-face orientation with the molecular center. An energy decomposition analysis is facilitated by means of fragment molecular orbital (FMO) approach. Using a set of appropriate structural descriptors and the extended tight binding (xTB) Hamiltonian, we give a statistical description of the gentiodelphin molecule in closed or partially-closed conformations.