The correlation functions of the regular tetrahedron and octahedron

Abstract: The expressions of the autocorrelation functions (CF) of the regular tetrahedron and the regular octahedron are reported. They have an algebraic form that involves the arctangent function and rational functions of r and (a + b r2)1/2, a and b being appropriate integers and r the distance. The CF expressions make the numerical determination of the corresponding scattering intensities fast and accurate also in presence of a size dispersion.