title: Shapes of a liquid droplet in a periodic box.
abstract: Within the coexistence region between liquid and vapor the equilibrium pressure of a simulated fluid exhibits characteristic jumps and plateaus when plotted as a function of density at constant temperature. These features exclusively pertain to a finite-size sample in a periodic box, as they are washed out in the bulk limit. Below the critical density, at each pressure jump the shape of the liquid drop undergoes a morphological transition, changing from spherical to cylindrical to slablike as the density is increased. We formulate a simple theory of these shape transitions, which is adapted from a calculation originally developed by Binder and coworkers [L. G. MacDowell, P. Virnau, M. Muller, and K. Binder, J. Chem. Phys. 120, 5293 (2004)]. Our focus is on the pressure equation of state (rather than on the chemical potential, as in the original work) and includes an extension to elongated boxes. Predictions based on this theory well agree with extensive Monte Carlo data for the cut-and-shifted Lennard-Jones fluid. We further discuss the thermodynamic stability of liquid drops with shapes other than the three mentioned above, like those found deep inside the liquid-vapor region in simulations starting from scratch. Our theory classifies these more elaborate shapes as metastable.
authors.affiliation: Università degli Studi di Messina, Dipartimento di Fisica e di Scienze della Terra, Contrada Papardo, I-98166 Messina, Italy.|Consiglio Nazionale delle Ricerche, IPCF, Viale F. Stagno d'Alcontres 37, I-98158 Messina, Italy.
authors.forename: Santi
authors.initials: S
authors.lastname: Prestipino
authors.affiliation: Università degli Studi di Messina, Dipartimento di Fisica e di Scienze della Terra, Contrada Papardo, I-98166 Messina, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Caccamo
authors.affiliation: Università degli Studi di Messina, Dipartimento di Fisica e di Scienze della Terra, Contrada Papardo, I-98166 Messina, Italy.
authors.forename: Dino
authors.initials: D
authors.lastname: Costa
authors.affiliation: Università degli Studi di Messina, Dipartimento di Fisica e di Scienze della Terra, Contrada Papardo, I-98166 Messina, Italy.
authors.forename: Gianpietro
authors.initials: G
authors.lastname: Malescio
authors.affiliation: Università degli Studi di Messina, Dipartimento di Fisica e di Scienze della Terra, Contrada Papardo, I-98166 Messina, Italy.
authors.forename: Gianmarco
authors.initials: G
authors.lastname: Munaò