Correlation functionals from the Møller-Plesset adiabatic connection: Accurate description of noncovalent interactions

The adiabatic connection (AC) that has as weak-interaction expansion the Møller-Plesset (MP) perturbation series has been recently shown to have a large coupling-strength expansion in terms of functionals of the Hartree-Fock density [1,2]. Based on these findings, in this work we introduce a new class of functionals that approximate directly the MP AC by interpolating between MP2 and the large-coupling strength limit, which is size consistent for fragments with a non-degenerate ground state [3]. These functionals have the same cost as double hybrids and capture non-covalent interactions (NCI) very accurately, without using dispersion corrections, as will be shown with results for several NCI test sets (S66, CT7, NGD8, DI6 and L7) and dissociation curves ranging from small dimers of noble gases to larger benzene-pyridine dimers.

[1] Seidl, M.; Giarrusso, S.; Vuckovic, S.; Fabiano, E.; Gori-Giorgi, P., J. Chem. Phys. 149, 241101 (2018).
[2] Daas, T. J.; Grossi, J.; Vuckovic, S.; Musslimani, Z. H.; Kooi, D. P.; Seidl, M.; Giesbertz, K. J. H.; Gori-Giorgi, arXiv:2009.04326 (2020).
[3] Vuckovic, S.; Gori-Giorgi, P.; Della Sala, F.; Fabiano, E., J. Phys. Chem. Lett. (2018), 9, 3137–3142.