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

TL;DR

The paper introduces an efficient scaling method that leverages MP2 and CCSD(T) energies to accurately compute non-covalent interaction energies with near-complete basis set quality, reducing computational cost.

Contribution

It presents a simple, transferable scaling procedure that improves the accuracy of non-covalent interaction energies using small basis set calculations.

Findings

Achieves near CCSD(T) accuracy with reduced computational effort.

Uses small basis sets with fitted scaling coefficients.

Effective across different intermolecular distances.

Abstract

Using the observed proportionality of CCSD(T) and MP2 correlation interaction energies [I. Grabowski, E. Fabiano, F. Della Sala, Phys. Chem. Chem. Phys. 15, 15485 (2013)] 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.