%0 Journal Article %@ 1948-7185 %A Ambrosetti, A %A Alfe, D %A Jr, DRA %A Tkatchenko, A %D 2014 %F discovery:1427811 %J Journal of Physical Chemistry Letters %N 5 %P 849 - 855 %T Hard Numbers for Large Molecules: Toward Exact Energetics for Supramolecular Systems %U https://discovery.ucl.ac.uk/id/eprint/1427811/ %V 5 %X Noncovalent interactions are ubiquitous in molecular and condensed-phase environments, and hence a reliable theoretical description of these fundamental interactions could pave the way toward a more complete understanding of the microscopic underpinnings for a diverse set of systems in chemistry and biology. In this work, we demonstrate that recent algorithmic advances coupled to the availability of large-scale computational resources make the stochastic quantum Monte Carlo approach to solving the Schrödinger equation an optimal contender for attaining “chemical accuracy” (1 kcal/mol) in the binding energies of supramolecular complexes of chemical relevance. To illustrate this point, we considered a select set of seven host–guest complexes, representing the spectrum of noncovalent interactions, including dispersion or van der Waals forces, π–π stacking, hydrogen bonding, hydrophobic interactions, and electrostatic (ion–dipole) attraction. A detailed analysis of the interaction energies reveals that a complete theoretical description necessitates treatment of terms well beyond the standard London and Axilrod–Teller contributions to the van der Waals dispersion energy. %Z This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Journal of Physical Chemistry Letters, copyright © American Chemical Society after peer review. To access the final edited and published work see http://dx.doi.org/10.1021/jz402663k