Understanding the Jahn-Teller distortions for the divacancy and the vacancy-group-V-atom pair in silicon

The Jahn-Teller (JT) distortions of the divacancy and the vacancy-group-V-atom pair in silicon are treated within a simple one-electron molecular orbital model associated with the dangling orbitals surrounding each vacancy. Properly instrumented, it predicts not only the correct sense of the distortion for the different charge states of the defects, but also provides a quantitative estimate of the magnitude of the JT distortions and the barriers for reorientation of each.