THE VERTEX CONTRIBUTION TO THE KIRSTE-POROD TERM

It is shown that, close to the origin, the correlation function [gamma (r)] of any N-component sample with interfaces made up of planar facet s is always a third-degree polynomial in r. Hence, the only monotonica lly decreasing terms present in the asymptotic expansion of the releva nt small-angle scattered intensity are the Pored [-2 gamma'(0(+))/h(4) ] and the Kirste-Porod [4 gamma((3))(0(+))/h(6)] contributions. The la tter contribution is non-zero owing to the contributions arising from each vertex of the interphase surfaces. The general vertex contributio n is evaluated in closed form and the gamma((3))(0(+)) values relevant to the regular polyhedra are reported.