The Q 3 population showed some discrepancy between experimental and simulated data, with the Q 3 population of NS08 obtained from NNMD simulation being lower than that of the experimental data; however, this result was the best match among the three simulated data cases. Bertani et al. The left panel in Fig. shows the experimental and simulated densities of Na the experimental data for compositions with R < 0.5; however, the monotonic increase in B 4 when R > 0.5 was an obvious inconsistency. This poor agreement may be explained by the role of the charge compensator in increasing Na + . Only the BO 4 -in the glass derived from CMD-Wang can play a part as a charge compensator, even when the glass composition in which the boron superstructure must be formed has a high R > 0.5. 106,107 The good agreement of the B 4 population given by CMD-Du was confirmed, as in the original study. The NNMD with the NNP developed here showed the same level of B 4 reproducibility as CMD-Du. The switch of the charge compensation mechanism by recombination of the borate network was correctly incorporated in NNP. The generation of boroxol rings and boron superstructures in NNMD-derived structures was observed by visual inspection of the snapshot. A more quantitative population analysis was also performed to enable understanding of the complex borate network changes that occurred with variation in R. The borons belonging to boroxol rings and boron superstructures were assigned on the basis of the NNMD-derived glass structure. All boron atoms were classified as either "ring" or "nonring" (B ring or B nonring ). The boron species were further classified into those with three-or four-coordination numbers (B 3 or B 4 ). Figure shows the populations of four types of boron species with variable R (left) and an illustration of boron species extracted from a glass structure of NB08 (right).