The collective response of deformed sodium clusters

We employ the structure-averaged jellium model (SAJM) to obtain the selfconsistent LDA Kohn-Sham ground state of axially deformed sodium clusters with broken leftright symmetry, and calculate the dipole-response of the low-energy isomers using the local RPA (LRPA) scheme in the range 7 < Z ≤ 59. We choose the multipole operators r ^P Y _LM (p=1,...,10; L=1,...,4, M=0,1) as coupled intrinsic modes of the electron system. The collective spectra are compared with recent measurements of the dipole absorption cross section performed by Meibom et al., and we find very good agreement of the positions and strengths of the leading collective modes in the measured range 47 < Z ≤ 59.