Oscillation modes in Coulomb clusters with variable charges

The mode spectra of small N=3N=3 and N=7N=7 clusters of dust particles with fluctuating charges are analyzed. It is demonstrated that the main effect related to the charge fluctuations is a splitting of the spectrum modes. The splitting depends the value of the charge variance. It is found that the most affected mode is the fundamental pure rotational mode. The least affected modes are pure translational ones while other modes demonstrate mixed response to the variance of the charge fluctuations.