Dixit, Purushottam D.Bansal, ArteeChapman, Walter G.Asthagiri, Dilip2018-06-292018-06-292017Dixit, Purushottam D., Bansal, Artee, Chapman, Walter G., et al.. "Mini-grand canonical ensemble: Chemical potential in the solvation shell." <i>The Journal of Chemical Physics,</i> 147, no. 16 (2017) AIP Publishing: https://doi.org/10.1063/1.4993178.https://hdl.handle.net/1911/102322Quantifying the statistics of occupancy of solvent molecules in the vicinity of solutes is central to our understanding of solvation phenomena. Number fluctuations in small solvation shells around solutes cannot be described within the macroscopic grand canonical framework using a single chemical potential that represents the solvent bath. In this communication, we hypothesize that molecular-sized observation volumes such as solvation shells are best described by coupling the solvation shell with a mixture of particle baths each with its own chemical potential. We confirm our hypotheses by studying the enhanced fluctuations in the occupancy statistics of hard sphere solvent particles around a distinguished hard sphere solute particle. Connections with established theories of solvation are also discussed.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlehttps://doi.org/10.1063/1.4993178