Reference: M. Korth, M. Pitonák, J. Rezác, and P. Hobza, "A Transferable H-bonding Correction For Semiempirical Quantum-Chemical Methods", J. Chem. Theory Comp. 2010, 6, 344352
Abstract:Semiempirical methods could offer a feasible compromise between ab initio and empirical approaches for the calculation of large molecules with biological relevance. A key problem for attempts in this direction is the rather bad performance of current semiempirical methods for noncovalent interactions, especially hydrogen-bonding. Based on the recently introduced PM6-DH method, that includes empirical corrections for dispersion (D) and hydrogen-bond (H) interactions, we have developed an improved and transferable h-bonding correction for semiempirical quantum chemical methods. The performance of the improved correction is evaluated for PM6, AM1, OM3 and SCC-DFTB (enhanced by standard empirical dispersion corrections) with several test sets for non-covalent interactions and is shown to reach the quality of current DFT-D approaches for these types of problems.