  Chiral structures have been found as the lowest-energy isomers of bare
(Au$_{28}$ and Au$_{55}) and thiol-passivated (Au$_{28}(SCH$_{3})$_{16}$ and
Au$_{38}(SCH_{3})_{24}) gold nanoclusters. The degree of chirality existing in
the chiral clusters was calculated using the Hausdorff chirality measure. We
found that the index of chirality is higher in the passivated clusters and
decreases with the cluster size. These results are consistent with the observed
chiroptical activity recently reported for glutahione-passivated gold
nanoclusters, and provide theoretical support for the existence of chirality in
these novel compounds.
