Influence of Force-Field Parameters on the Atomistic Simulations of Metallic Surfaces and Nanoparticles

Djebaili, Takieddine; Abel, Stéphane; Marchi, Massimo; Richardi, Johannes

doi:10.1021/acs.jpcc.7b09857

Cited by 4 publications

(3 citation statements)

References 35 publications

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“…Gold atoms and ligands were parametrized based on the model by Djebaili and co-workers, 43 which yields good agreement with experimental results. 53 Au−S interactions were modeled using a Lennard-Jones potential, which ignores features of the Au−S bonds (i.e., adatom coordination, 54 topsite grafting, 5 etc. ), but we justify our model a posteriori based on favorable comparison to experiments as described below.…”

Section: ■ Methodsmentioning

confidence: 99%

“…For this procedure, butanethiol ligands were modeled using a united atom model, where the SH, CH 2 , and CH 3 groups were each represented as a single interaction site. Gold atoms and ligands were parametrized based on the model by Djebaili and co-workers, which yields good agreement with experimental results . Au–S interactions were modeled using a Lennard-Jones potential, which ignores features of the Au–S bonds (i.e., adatom coordination, top-site grafting, etc.…”

Section: Methodsmentioning

confidence: 99%

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Effect of Core Morphology on the Structural Asymmetry of Alkanethiol Monolayer-Protected Gold Nanoparticles

Chew

Lehn

2018

J. Phys. Chem. C

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Gold nanoparticles (GNPs) are versatile materials suitable for various biological applications due to their tunable surface properties, but structure–function relationships between specific GNP components and GNP behavior are largely lacking. In this work, atomistic molecular dynamics simulations were used to study the influence of gold core morphology, size, and ligand length on the structure of uniformly nonpolar alkanethiol monolayer-protected GNPs in water. By use of a generalized system preparation workflow, three gold core models were selected for this study: (1) a uniformly spherical hollow gold core, (2) a spherical gold core cut from a bulk gold lattice, and (3) a faceted gold core obtained from variance-constrained semigrand-canonical simulations. Independent of the gold core morphology, we found that long alkanethiol ligands exhibit increased ligand order and form quasi-crystalline domains, or bundles, in which ligands orient in the same direction, leading to asymmetric monolayer structures. Faceted gold cores promote the formation of ligand bundles for short ligand lengths, but the influence of the gold core is diminished for long ligand lengths. We used a clustering algorithm to identify the subpopulation of bundled ligands and found that bundling leads to heterogeneous surface properties, whereby bundled ligands have a higher ligand order and lower surface area accessible for solvent interactions. These findings demonstrate the importance of GNP compositional features on monolayer structure, which could impact GNPs interactions with other molecules.

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Section: ■ Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Effect of Core Morphology on the Structural Asymmetry of Alkanethiol Monolayer-Protected Gold Nanoparticles

Chew

Lehn

2018

J. Phys. Chem. C

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“…First, classical force fields using, for example, Lennard-Jones parameters naturally lead to hollow sites as preferred adsorption sites (see, for example, the study in ref 26). This is because the hollow sites enable more contact between the adsorbing atom and the metallic atoms.…”

Section: Introductionmentioning

confidence: 99%

ReaxFF Simulations of Self-Assembled Monolayers on Silver Surfaces and Nanocrystals

Lahouari,

Piquemal,

Richardi

2024

J. Phys. Chem. C

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The self-assembled monolayers of alkanethiolates on Ag(111) surfaces and nanoparticles are studied using molecular dynamics. Reactive force fields allow simulations of very large systems, such as nanoparticles of 10 nm. Stable × °R ( 7 7 ) 19.1 assemblies are obtained as experimentally observed for these systems. Only nanoparticles smaller than 4 nm show spontaneous restructuring of the metallic core. The preferred adsorption site is found to be in an on-top position, which is in good agreement with recent X-ray absorption near-edge structure experiments. Moreover, similar distances between the sulfur headgroups are found on the facets and edges.

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Molecular interaction between asymmetric ligand-capped gold nanocrystals

Liu

Lü

Zhai

2019

The Journal of Chemical Physics

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Atomistic molecular dynamics simulations are performed to study the potential of mean force (PMF) between two asymmetric gold nanocrystals (NCs) capped by alkylthiols in a vacuum. We systematically investigate the dependence of the PMF on the sizes and capping ligand lengths of two NCs. The results show that the potential well depth scales linearly with increasing total length of two capping ligands on asymmetric dimers, but it hardly depends on the NC size. The predicted equilibrium distance between two asymmetric NCs grows significantly and linearly with the total size of two NCs and exhibits only a slight increase with increasing total ligand length. These findings are explained in terms of the amount of ligand interdigitation between NC surfaces as well as its alterations caused by the change in ligand length and NC size. Furthermore, we introduce a simple formula to estimate the equilibrium distance of two asymmetric NCs. On the basis of the computed PMFs, we propose an empirical two-body potential between asymmetric capped gold NCs.

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Influence of Force-Field Parameters on the Atomistic Simulations of Metallic Surfaces and Nanoparticles

Cited by 4 publications

References 35 publications

Effect of Core Morphology on the Structural Asymmetry of Alkanethiol Monolayer-Protected Gold Nanoparticles

Effect of Core Morphology on the Structural Asymmetry of Alkanethiol Monolayer-Protected Gold Nanoparticles

ReaxFF Simulations of Self-Assembled Monolayers on Silver Surfaces and Nanocrystals

Molecular interaction between asymmetric ligand-capped gold nanocrystals

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