A combined theoretical and experimental EXAFS study of the structure and dynamics of Au₁₄₇ nanoparticles

Abstract

We demonstrated the capability of combined EXAFS and DFT calculations for characterizing the structural and thermal properties of Au147 clusters.

Solving the Structure and Dynamics of Metal Nanoparticles by Combining X-Ray Absorption Fine Structure Spectroscopy and Atomistic Structure Simulations

“…For EXAFS data interpretation, MC simulations with empirical potential were recently employed by Duan and coworkers (38,41) to simulate EXAFS spectra in a heterogeneous system consisting of a mixture of pure Rh particles and bimetallic RhAu nanoparticles. Another MCrelated approach for simulation of EXAFS spectra was proposed by Duan and colleagues (32,44) for simulations of Au and Au Pt nanoparticles. In this case, DFT simulations were used to calculate a dynamical matrix and derive from it harmonic force constants and normal vibrational modes.…”

“…To summarize, atomic-scale simulation of nanomaterial structure, guided by XAS data, is a new and rapidly developing field. The importance of and growing interest in such studies are supported by a number of recent publications devoted to this topic (15,17,19,26,(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45). The approaches described in these articles often rely on similar ideas, but their implementation varies because such combined studies are still a relatively new tool for modeling NP structure.…”

Spherical harmonics based descriptor for neural network potentials: Structure and dynamics of Au147 nanocluster

“…Au 147 is one of the magic number clusters, and therefore the most stable structure assumed for it is an icosahedron. 20,23,24 We have generated a large number of isomers of Au 147 , and the structural pattern they follow is 105 atoms in the outer shell, 35 atoms in the middle shell, and 7 atoms in the inner shell, unlike an icosahedron that contains 13 atoms in the inner shell, 42 atoms in the middle shell, and 92 atoms in the outer shell. According to the ANN, and verified from DFT, the GM contains a 7-atom symmetric inner core structure, with the arrangement of the 35 atoms in the middle layer, also in a symmetric manner.…”

“…The assumed geometry of these clusters is icosahedron which has been recently published by Li et al 20 In this work, we have applied our potential to analyse the dynamics of Au 147 . By performing an EXAFS study 23,24 on bare and supported Au 147 , it has been recently shown that Au 147 exhibits an icosahedron geometry since the fitted parameters match with an icosahedron geometry. We have found that although being a magic cluster, Au 147 does not exhibit an icosahedron geometry.…”

Treatment of disorder effects in X-ray absorption spectra beyond the conventional approach

“…2014);House et al (2017)) or atomic displacement parameters obtained from lattice dynamics calculations(Duan et al (2016);Lapp et al (2018)). …”