Elastic and optical properties of alpha- and kappa-Al2O3

We present theoretical results for various properties of the stable alpha a nd metastable kappa phase of alumina, in particular elastic and optical pro perties. Two different computational methods have been used, the dacapo pla ne-wave-pseudopotential and the full potential linearized muffin tin orbita l methods. The calculations are based upon a recent determination of the cr ystal structure of kappa-Al2O3. Comparison between the two methods and avai lable experimental data show that they are both reliable for calculating th e ground-state and mechanical properties for this type of complex material. [S0163-1829(99)09519-3].