title: Detection and characterization of structural changes in the hard-disk fluid under freezing and melting conditions.
abstract: The fluid of two-dimensional hard disks is investigated over a range of densities by Monte Carlo simulations in order to detect and characterize structural changes which take place when the condition of freezing and melting is approached. A novel method is proposed based on the use of the Voronoi tessellation and a certain shape factor which turns out to be a clear indicator of the presence of different underlying substructures (domains). Close to the freezing condition the probability distribution of the shape factor develops a second distinct maximum corresponding to a predominant presence of near-regular hexagons, whereas the original peak, having its origin primarily in pentagons and distorted hexagons, diminishes and disappears at melting density.
authors.affiliation: Department of Physics, JE Purkyne University, 400 96 Ustí nad Labem, Czech Republic.
authors.forename: Filip
authors.initials: F
authors.lastname: Moucka
authors.forename: Ivo
authors.initials: I
authors.lastname: Nezbeda