Experimentally Validated Interface Structures of Pt Nanoclusters on MoS₂

We systematically predict the structures and energetics of nanoclusters on (001) using a genetic algorithm utilizing atomistic force fields and density functional theory, and predictive classical models for large clusters based on symmetry and Wulff-Kaischew construction. The supported n≤20 structures are validated atom-by-atom using aberration-corrected scanning transmission electron microscopy that can yield precise atomistic positions. We find that relatively small clusters grow with (111) orientation such that Pt is parallel to MoS₂, which is different from predictions based on lattice-match for thinfilms epitaxy. The underpinning of this growth mode is the tendency of the NPs to maximize the metal-sulfur interactions rather than to minimize lattice strain. We show that these findings are general and apply to other 4d and 5d metals despite the different levels of lattice misfit. This study underscores that a coordinated theoretical and experimental approach can determine the interfacial atomic structure and energetics with high fidelity, which is particularly valuable to quantitatively ascertain the structure-property relationships of supported clusters.