GNOM – a program package for small-angle scattering data processing

The Fortran program package GNOM carries out SAS data treatment and interpretation for the disperse non-interacting dilute systems of different types. A general operator method based on Tikhonov's regularization technique is used. Here a finite real-space distribution function [the correlation function p(r) for monodisperse systems and size distribution function D(R) for polydisperse ones] is searched for to fit the experimental data in accordance with the experimental conditions and the error bounds. It is possible to require non-negativity of the solution. The package GNOM is applicable for arbitrary experimental conditions (arbitrary weighting functions and form factors) and provides solutions stable to statistical noise and termination effects. The program makes it possible to treat together experimental curves from the same object measured under different experimental conditions and to choose the best model from the given set. Interactive and batch versions are available. The program is adapted to NORD, VAX and IBM-PC computers. It possesses convenient graphics possibilities.