Ab initio phonon spectra from a supercell approach

We discuss applications of a recently proposed direct space approach to the calculation of complete phonon spectra of crystals from first principles, which represents a generalisation of the standard supercell technique. On t he basis of atomic force calculations, it permits deduction of ab initio fo rce constants even for systems with long ranged lattice interaction without involving large supercells. We present results for phonon spectra of eleme ntal metals with FCC (Ir, Rh), BCC (Ba), and HCP (Ru) symmetry. For Ru, our calculations predict anomalous phonon dispersions in the vicinity of the M point. (C) 1999 Elsevier Science B.V. All rights reserved.