OPEN VERSUS CLOSED SYSTEMS IN STATIC NONLINEAR DIELECTRIC THEORY

The connections between the phenomenological dielectric coefficients o f closed and open systems are found. It is shown that, in the absence of any residual zero field polarization, the static linear dielectric constant in an open system is equal to that in the corresponding close d system. In contrast, it is shown that the nonlinear dielectric coeff icients of order four (and higher) are not equal in open and in closed systems Three applications of the relations between the coefficients of open and closed systems are made. The first is to the connections b etween the coefficients of a simple fluid composed of nonpolar, but po larizable, particles. The second is a rederivation of a classic result for electrostriction in open systems. The third is a discussion of a fluid composed of particles having permanent dipole moments but no pol arizability, with the restriction that, aside from the necessary long range correlations. there are no angular cross correlation terms.