 
Summary: Homogeneous nucleation of droplets from a supersaturated vapor phase
Michael P. Moody and Phil Attard
Ian Wark Research Institute, University of South Australia, Mawson Lakes SA 5095 Australia
Received 3 April 2002; accepted 17 July 2002
An approximate semianalytic theory is developed to describe the homogeneous nucleation of
droplets from a supersaturated vapor, beginning with a partition function and including rigorously
the translation and surface tension contributions. The liquid and vapor phases are treated as uniform
step density profile and may be described by any accurate equation of state. It is shown that the
classical approximation for the free energy of droplet formation may be derived from the present
theory by making additional approximations ideal gas, incompressible liquid , and the two are
compared for the case where the vapor phase forms a reservoir constant supersaturation . In the
case of a finitesized vapor phase, where the supersaturation decreases as the droplet grows, a free
energy minimum exists beyond the critical radius, and this stable droplet equilibrium is examined
in detail. Comparison with computer simulations proves the quantitative accuracy of the present
theory for a LennardJones system. Also derived is a new, formally exact expression for the surface
tension that is useful for computer simulations. © 2002 American Institute of Physics.
DOI: 10.1063/1.1505865
I. INTRODUCTION
If the pressure of a vapor phase, at some constant tem
perature, is increased beyond the liquidvapor coexistence
