Characterization of van der Waals Interactions with Energy Decomposition Analysis*

Van der Waals (vdW) interactions are ubiquitous in nature, and represent important contributions to the structure, stability, and function of many chemical systems. The absolutely localized molecular orbital energy decomposition analysis method (ALMO-EDA) allows for the characterization and quantification of intermolecular interactions such as London dispersion, the predominant attractive vdW component which is due to correlated fluctuations of the electron densities between molecules, and Pauli repulsion, the predominant repulsive vdW component which is a consequence of the antisymmetry of fermionic wave functions. Here we discuss our work studying vdW interactions calculated with ALMO-EDA in small and large molecular systems, and our findings regarding the role of nonlocal terms in approximate exchange-correlation density functionals in predicting vdW interaction energies, as well as many-body cooperativity in vdW interactions.

J. Chem. Theory Comput. 2019, 15, 2983-2995