This dataset contains tabular and image data from a computational study of vacancy formation, stacking defects, twinning, thermal evolution, and optical properties in noble-metal nanoparticles. The data were produced to investigate how nanoparticle size, vacancy concentration, spatial vacancy distribution, temperature, and crystallographic defects affect the internal morphology and physical properties of face-centered cubic nanostructures. The dataset covers gold cuboctahedral and spherical nanoparticle models, silver nanoparticles containing stacking faults or twin planes, and a schematic model of vacancy-driven twinning associated with phase segregation in Au–Pt nanoparticles.
Initially strain-free face-centered cubic nanoparticle models were populated with randomly distributed vacancies and subjected to energy minimization and molecular dynamics simulations. Gold models containing different vacancy concentrations were relaxed primarily using the Sutton–Chen potential implemented in the Cluster software, with selected simulations repeated using the Gupta potential. Thermal-evolution calculations were performed for a 5089-atom fcc spherical model containing 0–22% vacancies over a temperature range extending to the premelting region. Simulated X-ray diffraction patterns were analyzed using the multidomain X-ray diffraction method to estimate the effective number of crystalline domains. Particle density and mean size were determined from simulated small-angle X-ray scattering patterns calculated using the Debye summation approach. Local fcc, hcp, surface, and other atomic environments were visualized and analyzed using OVITO and, where appropriate, Blender. Selected silver nanoparticle models were relaxed using VASP with the PBE functional, and their optical and electronic properties were evaluated using time-dependent density-functional theory with a Hubbard U correction and superatomic projected density-of-states analysis.
The dataset is organized into machine-readable tabular files and graphical files. Table_1 contains the estimated number of crystalline domains in relaxed gold cuboctahedral nanoparticles of different sizes and vacancy concentrations. Table_S1, Table_S2, Table_S3, and Table_S4 contain, respectively, particle density derived from SAXS, mean particle size derived from SAXS, the number of domains derived from MDXRD, and potential energy per atom as functions of temperature and vacancy concentration. The corresponding PNG files reproduce the visual presentation of the supplementary tables, while the tabular versions provide the underlying numerical values.
The main-figure image files, FIG_1 and Fig_2–Fig_9, present the vacancy-driven twinning mechanism, the relationship between vacancy concentration and twinning, calculated XRD patterns, fcc and hcp atomic configurations, cross-twinned structures, temperature-dependent morphology evolution, absorption spectra, superatomic projected densities of states, and the proposed mechanism for bimetallic Au–Pt nanoparticles. The supplementary image files, Fig_S1–Fig_S10, provide additional morphology analyses, molecular-dynamics trajectories, potential-energy comparisons, comparisons between Sutton–Chen and Gupta potentials, XRD patterns for different vacancy distributions, direction-resolved optical spectra, surface and shape analyses, and a schematic representation of vacancy formation during atomic condensation. The supplementary-information PDF provides additional methodological explanations, supporting calculations, figure descriptions, and interpretation of the tabular and graphical data.
