# Soft-core mean spherical approximation

Junzo Chihara (along with Madden and Rice) extended the Percus Yevick equation for Lennard-Jones systems to provide a soft-core mean spherical approximation, the SMSA,

where is the pair potential, is the indirect correlation function, and , where is the Boltzmann constant.

## References[edit]

- Junzo Chihara "Integral Euqations for Fluids with Long-Range and Short-Range Potentials - Application to a Charged Particle System", Progress of Theoretical Physics,
**50**pp. 409-423 (1973) - Junzo Chihara "Integral Equations for Neutral and Charged Quantum Fluids Including Extension of the Percus-Yevick Equation" Progress of Theoretical Physics,
**50**pp. 1156-1181 (1973) - William G. Madden and Stuart A. Rice "The mean spherical approximation and effective pair potentials in liquids", Journal of Chemical Physics
**72**pp. 4208-4215 (1980)