Lattice dynamics in wurtzite semiconductors: The bond charge model of CdS

An extension of the adiabatic bond charge model of Rustagi and Weber is use d to study the lattice dynamic properties of wurtzite-type compounds. The m odel has been applied to the description of the phonon dispersion of CdS, w hich has been recently measured by neutron scattering. The agreement with t he neutron data is excellent with a small set of physically meaningful para meters. The eigenvector admixture of the E-2 modes, calculated at the Gamma -point, agrees with the experimental values obtained through the isotopic m ass dependence of the optical modes and ab initio calculations.