Silicon self-interstitial migration: Multiple paths and charge states

Total energy calculations performed to study the migration of silicon self-interstitials reveal a great complexity of migration paths. Si⁽⁺⁺⁾ and Si⁽⁰⁾ each migrate along more than one path and different paths from each other. Some paths involve interchange with bulk atoms. Electron-assisted transport occurs for the Si⁽⁺⁺⁾ stable tetrahedral site in all directions. Si⁽⁰⁾ has several almost-degenerate lowest-energy configurations. The lowest is the "exchange" configuration which also has the possibility of being negative (Si^(-)).