Percus-Yevick Solution Expansion for Hard Spheres

PERCUS-YEVICK SOLUTION EXPANSION FOR HARD SPHERES 

Almost all of the DFT calculations require a hard-sphere equation of state as part of the calculation. The van der Waal and other approximations have 

With this equation Percus and Yevick were able to extract various thermodynamic quantities and the virial coefficients. The virial coefficients agreed very well with the results of Monte Carlo calculations lending credibility to the approach. 

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