A recently developed non-conventional tight-binding method was applied in combination with molecular
dynamics to compute the geometric structures and cohesion energies of small stable pure Si clusters
containing from 3 to 8 atoms, in neutral, positive and negative charge states. The influence of the charge
state on the cluster configuration and cohesion energy is considered. The Anderson U(-) effect is observed
in Si3-Si5 clusters. Doubly positively charged states are found to be the most energetically stable form for
all clusters considered. The results computed with this semi-empirical approach are compared to predictions
from state-of-the-art ab initio methods
