An analytic structure factor for one-component fluid with a screened Coulomb plus power series interaction

From our previous analytic solutions of the Ornstein-Zernike equation in the mean-spherical approximation (Yasutomi M 2001 J. Phys.: Condens. Matter 13 L255), we obtain an analytic structure factor for one-component fluid with a screened Coulomb plus power series interaction expressed as

where c(r) is the direct correlation function, ϕ(r) is the interaction potential, k_B is Boltzmann's constant, T is a temperature, r is the interparticle separation, K^(τ) and z are constants, σ is the distance at contact of the particles, and L is an arbitrary integer. The results provide a useful model basis for studying a large variety of one-component fluids because almost all of the interaction potentials between particles can be well approximated by the above closure. As an example, we show a structure factor for a Lennard-Jones fluid.