First-principles calculations on the atomic and electronic structure of κ-Al₂O₃

The atomic and electronic structure and other structural properties of the metastable κ phase of Al₂O₃ have been investigated with a first-principles total-energy method based on density-functional theory at the local-density-approximation level, plane waves, and pseudopotentials. Calculated forces on each atom are used to relax the atomic positions to equilibrium within the restrictions given by what is known about the crystallography of κ-Al₂O₃. Among the structures with stacking-order sequence AcBcAbCb, one structure model is found to be the most stable one at zero temperature. Results are presented for atomic configuration, lattice parameters, bulk modulus, band structure, and electronic density of states. There is good agreement with the few available experimental results.