Theoretical study of multiatomic vacancies in single-layer hexagonal boron nitride

The physical properties of multiatomic vacancies are investigated by first-principles total-energy calculations. The formation energies of various vacancies as functions of chemical potential and charge states are calculated. The relationship between optimized atomic structures and charge states is analyzed. On the basis of the results, it is confirmed that the variations of formation energies and atomic structures are closely related to the changes in electronic states. In addition, the stabilities of generally large multiatomic vacancies are estimated on the basis of edges and corner energies. It is found that larger vacancies are not stable and have lower densities than smaller ones. The results are also compared with previous theoretical and experimental results. (C) 2017 The Japan Society of Applied Physics