This article describes the application of a genetic algorithm for the struc
tural optimization of 19-50-atom clusters bound by medium-range and short-r
ange Morse pair potentials. The GA is found to be efficient and reliable fo
r finding the geometries corresponding to the previously published global m
inima [Doye JPK, Wales DJ (1997) J Chem Soc Faraday Trans 93: 4233]. Using
the genetic algorithm, only a relatively small number of energy evaluations
and minimizations are required to find the global minima. By contrast, a s
imple random seal ch algorithm often cannot find the global minima of the l
arger clusters, even after many thousands of searches.