Optical and electronic properties of mixed Ag-Au tetramer cations

Abstract

We present experimental and theoretical studies of the optical response of mixed Ag(n)Au(+)(4-n) (n=1-3) clusters in the photon energy range ℏω = 1.9-3.5 eV. Absorption spectra are recorded by a newly built longitudinal molecular beam depletion spectroscopy apparatus providing lower limits to absolute photodissociation cross sections. The experimental data are compared to optical response calculations in the framework of long-range corrected time-dependent density functional theory with initial cluster geometries obtained by the unbiased Birmingham Cluster Genetic Algorithm coupled with density functional theory. Experiments and excited state calculations shed light on the structural and electronic properties of the mixed Ag-Au tetramer cations.

Optical Absorption of Small Palladium‐Doped Gold Clusters

“…[56] The rangeseparated exchange-correlation functional LC-ωPBEh was used, [57,58] due to its recently proven good performance for the structures and optical spectra of Au and AuAg clusters in this size range. [22,33] After local reoptimization, a frequency analysis was performed for all putative global minima to verify that each is a true minimum structure. Argon tagging was performed for each global minimum metallic cluster structure, considering all symmetry-inequivalent sites and subsequently optimizing local geometry.…”

“…[4] To enhance understanding, small unsupported atomic clusters, consisting of only a few atoms, represent ideal model systems for detailed investigations. [5] Moreover, many properties of small atomic clusters do not scale with size, are strongly composition and charge dependent, and can be very www.particle-journal.com www.MaterialsViews.com absorption measurements were carried out for Au 4-m Cu m + (m = 0-2) [32] and Ag n Au 4-n + (n = 1-3) [33] clusters in the gas phase.…”

Pool-BCGA: a parallelised generation-free genetic algorithm for the ab initio global optimisation of nanoalloy clusters

“…Since the electronic structure of large nanoparticles is expected to resemble the bulk phase, tailored model or empirical potentials (EPs) such as Gupta, 2 Sutton-Chen, 3 and Murrell-Mottram, 4 fitted to properties of the solid phase, enable a reasonable description of the PES. [11][12][13][14][15][16] For details on global optimisation algorithms, especially focused on genetic algorithms and basin hopping techniques, the reader is referred to the literature. nanoclusters, a quantum chemical treatment becomes necesa Eduard-Zintl-Institut, Technische Universität Darmstadt, Alarich-Weiss- Straße 8,64287 Darmstadt, Germany b Ernst-Berl-Institut, Technische Universität Darmstadt, Alarich-Weiss- Straße 8,64287 Darmstadt, Germany c School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom Authors to whom correspondence should be addressed.…”

Effects of Charge Transfer on the Adsorption of CO on Small Molybdenum‐Doped Platinum Clusters

“…A significant amount of research in the field of gas-phase clusters has been devoted to the influence of doping on the properties of clusters such as their structures, [22,23] optical responses, [24,25] and reactivity. [26,27] All these studies have shown that a single dopant atom can strongly influence the clusters' properties.…”