Accurate non-covalent interactions with basis-set corrections from interference-corrected perturbation theory: comparison with the S22B database

Abstract

Non-covalent interactions can usually be described accurately at the coupled-cluster level of theory using single, double and triple excitations, the latter within a perturbation-theory framework. However, since the computations with the corresponding coupled-cluster model, CCSD(T), are computationally very demanding, they can often not be carried out in large enough basis sets. This leads to a basis-set truncation error. To correct this error, a basis-set correction can be computed at the level of second-order Møller–Plesset (MP2) perturbation theory in the limit of a complete basis set, but such a correction tends to overestimate the magnitude of the basis-set truncation error. In the present work, we suggest to damp the basis-set correction obtained at the complete-basis-set MP2 level using interference factors for individual occupied orbital pairs. The approach is applied to the non-covalent interactions of the S22B database, where the interference correction turns out to be very small.

Keywords:

• S22 test set
• non-covalent interactions
• coupled-cluster theory
• explicit correlation
• interference factors

Acknowledgements

This research has been supported by the Deutsche Forschungsgemeinschaft through the Center for Functional Nanostructures (CFN, Project No. C3.3).

Notes

^a From Ref. [23].

^a From Ref. [23].