Structures and bonding properties of small Mo clusters

The structures and the binding energies of small Mo clusters from n= 2 to n= 8 are calculated within a local spin density approximation. Their ground -state structure indicates that the bonding properties of Mo atoms tend to be more directional than those of Cr or Nb atoms. This effect manifests itself in more buckling and lower symmetry in the ground-state configurations of Mo clusters. This will eventually result in different ground-state configurations compared to Cr or Nb clusters.The onset of a structural transition form a close-packed structure towards a body-centered cubic structure, as related to the appearance of a square-shaped face, is already seen in Mo6 and in Mo8