Journal of Applied Crystallography

Volume 26, Part 4 (August 1993)

short communications

J. Appl. Cryst. (1993). 26, 612-615 [ doi:10.1107/S0021889893001335 ]

On the shape of the radial distribution function of an assembly of monodisperse ellipsoidal scatterers

E. Caponetti, M. A. Floriano, E. Di Dio and R. Triolo

Abstract: It is well known that the small-angle scattering pattern of an assembly of monodisperse ellipsoidal particles is equivalent to the one obtained from an assembly of polydisperse spherical scatterers. In this paper, it is shown that the radial distribution function that one obtains from a system of monodisperse ellipsoids has a shape very different from that of any common size distribution function (Schulz, Gaussian, rectangular, ) usually assumed for polydisperse systems. From a theoretical point of view, the scattering pattern arising from a system characterized by a small size anisotropy is distinct from that arising from one containing spherical particles with a narrow radii distribution but, experimentally, such a distinction can be made only when a substantial deviation from a monodisperse spherical system is present.