LINEAR-RESPONSE CALCULATIONS WITHIN THE LINEARIZED AUGMENTED PLANE-WAVE METHOD

The linear-response approach to density-functional calculations in the local-density approximation is more efficient than traditional superc ell and dielectric matrix techniques for the calculation of physical p roperties such as phonon frequencies. We have implemented this approac h within the framework of the linearized augmented plane-wave method, which should bring it to bear on systems containing transition-metal a nd other elements that have localized orbitals. The formulation for th is implementation is presented. The method is applied to the calculati on of phonon spectra, Born effective charges, and dielectric constants for semiconductors. Results for phonon spectra and Born effective cha rges are in good agreement with experiment.