LATTICE DYNAMICS OF AN F-TYPE ICOSAHEDRAL QUASICRYSTAL

Abstract

By using a matrix-continued fraction approach we calculate the density of vibrational states (DOS) of a tiling model based on the 6D face centered lattice. Parameters of the Lennard-Jones pair interaction are obtained from relaxation calculations. With a ternary decoration the tiling was found to be stable. The DOS was approximated by weighting the local DOS (LDOS) of the allowed vertex configurations by their relative frequencies in the infinite tiling. These frequencies were obtained by using extended deflation rules. Results of this approach are compared to exact finite cluster calculations and an embedded cluster approach. We find the DOS to consist of a single band (in our resolution) and a rich structure at higher frequencies.