Molecular aggregates, which are held together by such non-bonded interactions, may present a remarkable challenge, as their relative populations are governed by a delicate balance of enthalpic and entropic contributions. Indeed, predicting these populations requires (i) an accurate description of non-bonded interactions, which determine the enthalpic component, and (ii) a thorough accounting of the extensive range of conformers arising from complex potential energy surfaces (PESs) with numerous energetically accessible minima, which govern the entropic contribution.