AN IMPROVED METHOD FOR THE NORMALIZATION OF THE SCATTERED INTENSITY AND ACCURATE DETERMINATION OF THE MACROSCOPIC DENSITY OF NONCRYSTALLINEMATERIALS

During the past few years, several studies have been carried out of th e structural characterization of amorphous materials using the Monte C arlo method. It has been shown that a variety of errors gives rise to pronounced artifacts in the R-space correlation functions, which may h inder the accurate interpretation of the Monte Carlo results. The elim ination of these ambiguities, particularly for heteroatomic systems, d emands very careful experiments in association with careful error anal ysis. Recently, Kaszkur [J. Appl. Cryst. (1990), 23, 180-185] presente d a theory describing some convolutional properties of the reduced int erference function. This procedure enables an estimation of the normal ization constant (in all probability, nowadays, one of the more seriou s limitations in obtaining significant and reproducible radial distrib ution functions) with a high degree of accuracy. Since the Kaszkur for mulation is limited to monoatomic substances, the present work recalls his basic arguments with the aim of extending them to the most genera l case of heteroatomic materials. In addition, the proposed procedure allows an overall insight into the quality of the measured data and de termination of the macroscopic density on the basis of the scattered i ntensities. The success of the procedure is proved by its application to two experimental data sets and one simulated example.