Accurate non-covalent interaction energies via an efficient MP2 scaling procedure

Abstract Using the observed proportionality of CCSD(T) and MP2 correlation interaction energies [17] we propose a simple scaling procedure to compute accurate interaction energies of non-covalent complexes. Our method makes use of MP2 and CCSD(T) correlation energies, computed in relatively small basis sets, and fitted scaling coefficients to yield interaction energies of almost complete basis set limit CCSD(T) quality. Thanks to the good transferability of the scaling coefficients involved in the calculations, good results can be easily obtained for different intermolecular distances.