A genetic algorithm study on the most stable disordered and ordered configurations of Au38-55

We used the genetic algorithm, with a Gupta n-body potential, to study stru ctures of the ground states and near ground ordered states of medium-sized Au-n (n from 38 to 55) clusters. It is found that the most stable configura tions are mainly disordered with the ordered isomers very close in energy t o the ground state. The lowest-lying ordered structure changes from close p acked mode to icosahedron-like structure with increasing cluster size. A co mmon neighbor analysis (CNA) was applied to demonstrate the structural evol vement. (C) 2000 Elsevier Science B.V. All rights reserved.