Calculation of defect in bulk of a wafer model

I’d like to estimate defect in bulk of a model. When cheking literatures, typical SiO2 has something like defect density of 5x10^17 cm^-3. Is it possible to perform similar calculation using ASE SiO2 model? I could not find similar topic, so I’d like to get some hints from this community. thank you in advance.

In addition, is it possible to calculate void/vacancy of a model?