Spin preference of small metal clusters

Spin preference of copper, silver, and gold clusters is discussed. While the high-spin states prefer D4h or D3h geometries, low-spin states prefer D2h or C2v geometries due to vibronic interactions. Regardless of the orbital degeneracy, the vibronic interactions are enough large to stabilize the low-spin states. Origin of the low-spin preference is related to absolute hardness of the atoms and unique multicentered bondings.