Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · physics/9711005

Influence of Dynamics on Magic Numbers for Silicon Clusters

A. R. Porter·R. W. Godby
View original source ↗Read source document ↗Export metadata ↓

Abstract

We present the results of over 90 tight-binding molecular-dynamics simulations of collisions between three- and five-atom silicon clusters, at a system temperature of 2000K. Much the most likely products are found to be two 'magic' four-atom clusters. We show that previous studies, which focused on the equilibrium binding energies of clusters of different sizes, are of limited relevance, and introduce a new effective binding energy which incorporates the highly anharmonic dynamics of the clusters. The inclusion of dynamics enhances the magic nature of both Si4 and Si6 and destroys that of Si7.

Explore related subjects

physics.atm-cluscond-mat.mtrl-sci

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A. R. Porter, R. W. Godby. 1997-11-06. Influence of Dynamics on Magic Numbers for Silicon Clusters. https://arxiv.org/abs/physics/9711005

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Critical velocity and dissipation mechanism in finite superfluid $^4$He nanodroplets

A hallmark of superfluidity is the frictionless motion of an object below the Landau critical velocity; Whether this concept applies to nanoscale droplets remains unclear. Using time-dependent density functional theory, we investigate the motion of a sodium atom on the surface and inside a superfluid helium nanodroplet. For surface motion, we identify a critical velocity above which energy dissipation through ripplon excitation and the formation of surface-bound quantized vortices leads to rapid deceleration. Inside the droplet, the atom is slowed down to a steady-state velocity that depends on the initial speed, contrasting experiments reporting a critical velocity for dopants ejected from droplets [Phys. Rev. Lett. 111, 153002 (2013)]. Remarkably, the velocity of the ejected atom is nearly independent of its initial velocity. We demonstrate that this behavior results from the bursting of the bubble surrounding the atom at the droplet surface, challenging the previous experimental interpretation.

physics.atm-clus↗
arXiv2026

Correlated detection of electrons and ions emitted from laser-induced nanoplasmas in doped helium nanodroplets in the single-shot single-cluster regime

We present single-cluster single-shot correlated measurements of electron velocity-map images and ion time-of-flight traces from individual laser-induced nanoplasmas in xenon-doped helium nanodroplets. Simultaneous detection associates the ion composition, ion kinetic energies, and electron energies with the same nanoplasma event. The detected ion composition separates events into populations dominated by He+ mono-cations versus those dominated by He^{2+} di-cations, with markedly different ion energies and electron kinetic energies. The He+-dominated population correlates well with low electron kinetic energies (< 0.5 eV), whereas the distribution of maximum electron kinetic energies for the He^{2+}-dominated population shows a peak around 1 eV. Molecular dynamics simulations averaged over the focal volume suggest that local laser intensity contributes to this separation. These correlations provide single-event observables for classifying nanoplasmas and will support real-time shot-to-shot sorting in single-particle coherent diffractive imaging experiments.

physics.atm-clus↗
arXiv2026

Ultrafast Proton-Induced Collective Dynamics Regulated by Water-Mediated Hydrogen-Bond Networks in Liquids

Photoinduced proton dynamics in liquids couple molecular reactions to nonequilibrium charge transport, yet the role of alkyl C-H sites as proton sources remains poorly understood. Combining optical-pump terahertz-probe spectroscopy with real-time time-dependent density-functional-theory simulations, we investigate ultrafast proton dynamics following strong-field ionization of liquid ethanol and hydroxyl-free ethyl acetate. Isotope-substitution and control experiments support the identification of alkyl C-H groups as the proton source. The released protons induce quasi-free-electron localization on a timescale of hundreds of femtoseconds, manifested as a characteristic V-shaped transient in terahertz absorption. In ethanol-water mixtures, trace water enhances hydrogen-bond-network connectivity and facilitates proton transfer to ethanol O-H sites, suppressing the transient absorption dip. These findings identify photoactivated C-H sites as proton sources in liquids and reveal how hydrogen-bond networks regulate the ensuing proton and electron dynamics, linking local bond cleavage to the ultrafast charge response of the surrounding liquid.

physics.atm-clus↗