Perturbation theory for a polarizing liquid

The thermodynamic perturbation theory is applied to polar polarizing liquids. A system of rigid dipoles is chosen as a basis, and the magnitude of the dipole moment is determined from the Gibbs-Bogolyubov variational principle. The equation of state obtained within the framework of the variational approach is used for calculating the free energy of a model system of polarizing dipolar solid spheres. Good agreement is obtained with results of computer experiment.