Charge ordering induced metal-semiconductor transition in Ag2BiO3: A first-principles study

GGA calculating results indicate that Ag2BiO3 in Pnna phase, in which the bismuth atoms occupy the same Wykoff positions, exhibits metallic conductivity, while in Pnn2 and Pn phases, Ag2BiO3 exhibits semiconducting character, which is in agreement with the experimental results. Charge ordering is indeed induced by the crystal inversion twin in the Pnn2 phase compared with the Pnna phase.