Thermodynamics and structural properties of the dipolar Yukawa fluid

We report computer simulations and a theoretical study of the thermodynamic s and structure of a dipolar Yukawa system. A comparison between the analyt ical mean spherical approximation (MSA) solution, perturbation theory and M onte Carlo simulation data of pressure, internal energy and dielectric cons tant is given. In the perturbation theory, the MSA solution of hard core Yu kawa fluid is used as a reference system. It was found that the MSA solutio n is reasonable only at lower dipole moments, while the perturbation theory gives good results at low and high values of dipole moment. Liquid-vapor c oexistence data of dipolar Yukawa fluid are also obtained by Monte Carlo si mulation and by both MSA and perturbation theory. It was found that at high dipole moments the liquid-vapor equilibrium disappears while chain-like st ructures appear in the low density fluid phase. The appearance of chain-lik e structures of dipolar Yukawa fluid is discussed in comparison with the St ockmayer fluid. (C) 1999 American Institute of Physics. [S0021-9606(99)5022 5-0].