Spatial uniformity as a principle for determination of atomistic structural models

We discuss the concept of structural uniformity as a tool for model construction, and employ the recently proposed reverse Monte Carlo + invariant environment refinement technique (RMC+INVERT) method to create computer models of amorphous materials. We further develop the RMC+INVERT method, and apply it to model glassy GeO₂, by jointly fitting partial pair-correlation functions rather than the total correlation function as in previous calculations. Then the technique was applied to model water-ice (a-H ₂O), for which the uniformity is imposed on the medium range order. For these two cases, we found that imposing spatial uniformity may significantly improve the atomistic model, and the RMC+INVERT method is shown to offer significant advantage over the conventional RMC technique for particular systems.