ABSTRACT: Although several thiolate-protected Au nanoclusters
have yielded to total-structure determination, the ligand-conformation
energy landscapes and how they affect the relative stability of
the whole clusters are not well understood. In this work, we employ
a force-field-based approach to perform the ligand-conformation
search for isolated thiolate-protected Au nanoclusters using
Au25(SR)18 (R = C2H4Ph) as an example. We find that the
ligand-conformation energy landscape of Au25(SC2H4Ph)18 comprises
multiple low-energy funnels of similar stability instead of a
single global minimum. In fact, we find slightly more stable
conformations of isolated Au25(SC2H4Ph)18 than those observed in
the experiment from a crystalline state, indicating that specific
environments such as crystal packing and solvents may all affect the
ligand conformation. This work reveals the role of ligand
conformation in the cluster energy landscape.