An extension of the Onsager theory of dielectric polarization is presented. The local
dielectric constant is approximated by the macroscopic dielectric constant of the fluid in a
region outside a molecule and its first shell of neighbors rather than in the entire region
exterior to the molecule. In addition to the molecular dipole moment, the average value< cos
γ> Av of the cosine of the angle between neighbor dipoles is a determining factor. Hindered
relative rotation of neighboring molecules produces a correlation between their orientations …