Toward an accurate self-interaction binding energy of magic cluster TiAu₄

We performed coupled-cluster calculations to determine the intermolecular interaction energy between two TiAu₄ clusters. Our ab initio calculations predict that the binding energy is 2.89 eV, which is somewhat larger than the known binding energy of 2.0 eV for TiH₄-TiH ₄. The intermolecular binding energy is relatively high, despite TiAu₄ having all the attributes of a magic cluster. The favorable orbital interaction between occupied Au(6s) and unoccupied Ti(3d) orbitals leads to the strong dimeric interaction for TiAu₄-TiAu₄.