  We investigate the quality of structural models generated by the Reverse
Monte Carlo (RMC) method in a typical application to amorphous systems. To this
end we calculate surrogate diffraction data from a Li2O-SiO2 molecular dynamics
(MD) simulation and use the total scattering function, in addition to minimal
pair distances and coordination numbers of silicon (oxygen) to oxygen (silicon)
ions, as input for the RMC modeling. Then we compare partial radial
distribution functions, coordination numbers, bond angles, and ring sizes
predicted by the RMC models with those of the MD system. It is found that
partial distributions functions and properties on small lengths scales, as
distributions of coordination numbers and bond angles, are well reproduced by
the RMC modeling. Properties in the medium-range order regime are, however, not
well captured, as is demonstrated by comparison of ring size distributions. Due
care therefore has to be exercised when extracting structural features from RMC
models in this medium-range order regime. In particular we show that the
occurrence of such features can be a mere consequence of the chosen starting
configuration.
