Fig. 5: Interaction energy and molecular polarizability along non-covalent bond dissociations.

a The delta metric (Δ, see formula on the plot) results are shown for four Density Functional Theory methods: PBE0¹⁷ including Many-Body Dispersion (MBD)^18,19, D4^23,24, and eXchange-hole Dipole Moment (XDM)⁹⁵, ωB97X-V⁷⁰; two semiempirical methods: DFTB3¹⁵+MBD^18,19, GFN2-xTB¹⁶; and a classical force field method: AMBER-GAFF2¹¹. b Average of the absolute difference of predicted interaction energy with the Local Natural Orbitals - Coupled Cluster with Singles, Doubles, and perturbative triplets (LNO-CCSD(T)) reference along the dissociation of the non-covalent bond of a selection of dimers. The average is calculated at each multiplicative distance factor q (ranging from 0.9 to 2.0), defined as the ratio between the bond length and the equilibrium non-covalent bond length for the corresponding dimer. The average is shown for six selected molecular dimers: F2B1, F2I1, SF2B2, SF2I2, L2B3, and L2I3, using the same methods and corresponding color highlights as in (a). c Average of the difference in the molecular polarizability of the dimer and the sum of isotropic polarizabilities of its corresponding monomers at each distance factor q. The results are shown as an average (points) with a standard error (background) over all 128 non-equilibrium dimers in the QUantum Interacting Dimer (QUID) dataset, split by structural type in Linear, Semi-Folded, and Folded.