DETERMINATION OF THE ATOMIC-STRUCTURE OF DISORDERED-SYSTEMS ON THE BASIS OF LIMITED Q-SPACE INFORMATION

It is shown that the reverse Monte Carlo method [R. L. McGreevy and L. Pusztai, Mol. Sim. 1, 359 (1988)] is able to provide the correct pair-correlation function even if the structure factor is available over only a very limited momentum-transfer range. In some favorable cases, the Q range can be as short as 0.5 3 A-1. The possibility of separating the partial pair-correlation functions of two component systems, based on three independent structure factors of limited Q range, is also demonstrated. Cosine distributions of bond angles are not sensitive, either, to the reduction of Q space information. Effects of omitting the first (two) peak(s) of the structure factor have also been investigated. It is concluded that in some cases relatively small parts of the full structure factor may be sufficient for extracting all the available information on the structure of a disordered system. © 1995 The American Physical Society.