title: Wertheim and Bjerrum-Tani-Henderson theories for associating fluids: a critical assessment.
abstract: Two theories for associating fluids recently used to study clustering in models for self-assembling patchy particles, Wertheim's and Bjerrum-Tani-Henderson theories, are carefully compared. We show that, for a fluid allowing only for dimerization, Wertheim theory is equivalent to the Bjerrum-Tani-Henderson theory neglecting intercluster correlations. Nonetheless, while the former theory is able to account for percolation and condensation, the latter is not. For the Bjerrum-Tani-Henderson theory we also rigorously prove the uniqueness of the solution for the cluster's concentrations and the reduction of the system of equations to a single one for a single unknown. We carry out Monte Carlo simulations of two simple models of dimerizing fluids and compare quantitatively the predictions of the two theories with the simulation data.
authors.affiliation: Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari Venezia, Calle Larga S. Marta DD2137, I-30123 Venezia, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Fantoni
authors.affiliation: Dipartimento di Fisica dell' Università and IOM-CNR, Strada Costiera 11, 34151 Trieste, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Pastore