Meta-stability through intermolecular interactions protecting the identity of atomic metal clusters: ab initio evidences in (Cu 5 -Cu 5 ) n ( n < 3) cases.

Recent developments in new synthesis techniques have allowed the production of precise monodisperse metal clusters composed of a few atoms. These atomic metal clusters (AMCs) often feature a molecule-like electronic structure, which makes their physical and chemical properties particularly interesting in nanotechnology. Regarding potential applications, there is a major concern about the sintering of AMCs in nanoparticles due to the loss of their special properties. In this work, multireference ab initio theory is applied to demonstrate the formation of coupled AMC-AMC clusters in which the AMC partners maintain their 'identity' to a large extent in terms of their initial structures and atomic Mulliken charges, and their further oligomerization.