From NSDL Materials Digital Library Wiki
The Yukawa pair potential is used to model the interaction between charge stabilized colloids. It is a purely repulsive potential when considered two particles with like charge; oppositely charged particles will exhibit an attraction.
The typical formulation of the Yukawa potential is as follows :
Often in Monte Carlo Simulation (MC) studies, the hard-core formulation of the Yukawa potential is used :
Where in both cases σ, κ, and ε are the particle diameter, inverse screening length (inverse Debye length), and surface potential respectively.
This potential is shown to the right for various combinations of κ and ε. It is important to note that ε adjusts the height at the surface. A large value for κ results to a short-range potential, where as a small value results in a long-range potential.
The phase behavior has been investigated in two  and three dimensions [1,3,4] using Monte Carlo Simulation (MC).
-  El Azhar F, Baus M, Ryckaert JP, et al. Line of triple points for the hard-core Yukawa model: A computer simulation study, JOURNAL OF CHEMICAL PHYSICS 112 (11): 5121-5126 MAR 15 (2000)
-  LOWEN H. STRUCTURE AND BROWNIAN DYNAMICS OF THE 2-DIMENSIONAL YUKAWA FLUID, JOURNAL OF PHYSICS-CONDENSED MATTER 4 (50): 10105-10116 DEC 14 1992
-  Auer S, Frenkel D. Crystallization of weakly charged colloidal spheres: a numerical study, JOURNAL OF PHYSICS-CONDENSED MATTER 14 (33): 7667-7680 AUG 26 2002
-  HAGEN MHJ, FRENKEL D. DETERMINATION OF PHASE-DIAGRAMS FOR THE HARD-CORE ATTRACTIVE YUKAWA SYSTEM , JOURNAL OF CHEMICAL PHYSICS 101 (5): 4093-4097 SEP 1 1994