Super-Excimer: Anomalous Bonding in a Metastable Excited-State Dimer of Superatomic Dimers

A new type of excimer formation was reported, which stems from an unexpected discovery of a short-lived excited-state dimer of superatomic dimers. In theoretical investigation of the dimer formation, it was found that the physical adsorption states maintain the closed-shell properties of the dimeric units via van der Waals interaction, while the chemical adsorption excited state is a broken-symmetry (BS) state, having a higher energy of about 0.5 eV. Potential energy surface calculations indicate that the short-lived metastable chemical bonding state can transform into energetically lower physical adsorption states by crossing a shallow energy barrier and eventually disintegrate into two ground-state dimers. Since the basic unit is a superatomic cluster, the chemical adsorption state discovered may be called super-excimer , which opens up a new avenue for the discovery of tailorable excimer materials.

Automated summary

A new type of excimer formation was discovered, which originates from the short-lived excited-state dimer of superatomic dimers. Theoretical investigation reveals that the physical adsorption states and the chemical adsorption excited state have different energy levels and properties, with the chemical adsorption state able to transform into the physical adsorption state by crossing a shallow energy barrier.