COMPARED PERFORMANCES OF THE MOLECULAR-ORBITAL AND DENSITY-FUNCTIONALTHEORIES FOR FRAGMENTS OF BIOMOLECULES

As a preliminary to quantum-mechanical studies of nucleic acids, the p ossibilities of the molecular orbital (MO) method at the MP2 level and of the density functional theory (DFT) have been examined for typical fragments of nucleosides: methanol, tetrahydrofuran, 3-hydroxytetrahy drofuran and uracil. The results obtained from both methods using pola rized split-valence basis sets are found to be consistent with each ot her, except for small but significant differences that are possibly re lated to the neglect of DFT self-interaction corrections.