This work presents a computational modelling study of CaSIO3 glass, with the aims of examining the local atomic environment of Ca, the interpretation of the Ca-Ca distribution, and the influence of network topology. One model was constructed using the molecular dynamics method and has a broad Qn distribution, whereas another model was constructed using the reverse Monte Carlo method to control network topology and has a narrow Qn distribution. In both models the majority of bridging oxygens are also co-ordinated to Ca. Hence, nonbridging oxygens by themselves are not sufficient to define the interface between network former and network modifier regions. Despite having different Qn distributions, both models have similar x-ray diffraction structure factor and Ca-Ca distribution, and these are in fair agreement with experimental results.
