What is the charge range for two N vacancies in a defect crystal?

[jackwangsg]

TL;DR Summary

one vacancy have different charged state, for example one N vacancy range [0,+3], what the charge range for two N vacancies?

Hi, all
I am studying the defect formation energy calculations for defect crystal. One vacancy have different charged state, for example one N vacancy range [0,+3], what the charge range for two N vacancies? From chemistry, two N vacancies should be have max charge: +6. However, most reference still use the charge range [0,+3]. how to explain this ? Thank you

 

[anuttarasammyak]

I am not accustomed to your [0,+3]. Referring to https://en.wikipedia.org/wiki/Nitrogen-vacancy_center, I understand that at the vacancy 3 electrons come from neighboring C atoms, an electron pair come from N atom and frequently one electron come from outside to become $NV^-$ so total six electrons are involved. May I understand that your [0,+3] notation correspond to it ?