B. Borstnik et al., ANOMALOUS CLUSTERING AND EQUATION-OF-STATE BEHAVIOR AS THE ADHESIVE-DISK LIMIT IS APPROACHED, The Journal of chemical physics, 106(23), 1997, pp. 9762-9768
The structure of clusters of two-dimensional particles interacting wit
h a hard-core square-well pair potential is analyzed in order to demon
strate how thermodynamic stability ceases to exist when the system app
roaches the Baxter's sticky limit, It is shown that the dependence of
the sizes and the radii of gyration of the clusters of two-dimensional
sticky disks behave qualitatively differently when the number of part
icles in tile cluster exceeds 6, Cluster sizes with n < 7 exhibit smoo
th transition when the Baxter limit is approached while clusters with
seven more disks experience an anomalous transition towards a state of
maximal connectedness. The configuration integrals that are needed to
describe clusters of seven particles are then used to demonstrate the
way in which their contribution to the virial expansion of the equati
on of state causes it to become pathological. From the results, it is
concluded that the system will show the anomalous thermodynamic behavi
or associated with the approach to instability only for well widths of
the order of 10(-4) of the hard core diameter or less, The status of
using approximate adhesive-particle results as approximate square-well
-particle results is then summarized, It is pointed out that there is
a fundamental defect in all currently available methods of approximati
ng square-well liquid-gas phase separation using adhesive-sphere resul
ts. (C) 1997 American Institute of Physics.