Exploring Point Defects in Rb2O via First-Principles Calculations
Abstract
Ab initio calculations for dirubidium oxide (Rb2O) in antifluorite structure with four types of point defects, rubidium vacancy, oxygen vacancy, rubidium defect, and oxygen defect have been performed by the plane-wave self-consistent field based on density functional theory with generalized gradient approximation functional of Perdew-Burke-Ernzerhof exchange-correlation. For structural optimization, the Broyden-Fletcher-Goldfarb-Shanno algorithm is used. Defect formation energies are calculated under lattice relaxation for one unit cell of Rb2O containing eight atoms of rubidium and four atoms of oxygen. For defect and vacancy structures, total energy, lattice constant, and vacancy formation energy are computed and discussed.