A Quantum Chemical Method for Dissecting London Dispersion Energy into Atomic Building Blocks.

London dispersion (LD) forces are ubiquitous in chemistry and biology, governing processes such as binding of drugs to protein targets, the formation and stability of reaction intermediates, and the selectivity of enantioselective transformations. Developing an experimental or quantum chemical method to quantify atomic contributions to LD energy could open up new pathways for controlling reaction selectivity and guiding molecular design. Herein, we initially introduce Atomic Decomposition of London Dispersion energy (ADLD), a computational method that provides atomic-level resolution in quantifying LD energy at the "gold standard" level of quantum chemistry. Through a series of case studies, we reveal that LD is highly sensitive to variations in the electronic structure, including spin state, charge, and valence bond resonance effectskey factors often overlooked. Furthermore, we uncover the fundamental origin of the recently proposed gravitational-like relationship describing the distance dependence of LD energy in molecular systems. In doing so, we reconcile these recent findings with Fritz London's original formulation in 1930, offering a unified perspective on the fundamental nature of LD forces.