Study of GaAs cluster ions using FP-LMTO MD method

Using full-muffin-tin-orbital molecular-dynamics (FP-LMTO-MD) method, we have investigated the electronic and geometric structures of GanAsn (n=4,5,6n=4,5,6) cluster ions in detail. Their lowest energy structures are found. We have also investigated the evolution of some Ga4As4, Ga5As5 and Ga6As6 clusters as a function of charging. Our calculations suggest that some of the lowest energy structures for the cluster ions are different from those of the corresponding neutral clusters. Upon charging, the structures will undergo structural distortion because of the electrostatic repulsion among the charged atoms. Gallium atoms are more easily on capped atomic positions than arsenic atoms in the negative GanAsn clusters.