Kerr constant and related quantities in terms of atom–atom correlation functions

We find an expression for ℱPl(ŝ1ŝ2) h (12) dΩ1dΩ2dr in terms of atom–atom correlation functions, where h (12) is the full molecular pair correlation function, ŝi is a unit vector that describes the orientation of the ith molecule, and Pl is the Legendre polynomial. For l=1 the result yields our earlier expression for the dielectric constant of a polar (nonpolarizable) fluid. For l=2, the result yields the Kerr constant for a nonpolar fluid of linear molecules, and is also relevant to the theory of dipolarized light scattering and quadratic field effects in NMR theory.