Geometrical structures and vibrational spectroscopy of medium-sized neutral Aun (n=17–26n=17–26) clusters

Geometrical structures and corresponding vibrational spectra of neutral Aun (n=17–26n=17–26) clusters are investigated by density-functional theory. We found their far-infrared spectra are distinctively structure-dependent, providing an efficient way to identify their structures. A new ground-state Au23 bulk-fragment isomer is found, exhibiting also some specific low-frequency far-infrared peaks for cage-like structure.