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Related papers: Packing Transitions in Nanosized Li Clusters

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We present a statistical fragmentation study of doubly charged alkali (Li, Na, K) and antimony clusters. The evaporation of one charged trimer is the most dominant decay channel (asymmetric fission) at low excitation energies. For small…

Materials Science · Physics 2009-10-28 M. E. Madjet , P. A. Hervieux , D. H. E. Gross , O. Schapiro

We study the optimal packing of short, hard spherocylinders confined to lie tangential to a spherical surface, using simulated annealing and molecular dynamics simulations. For clusters of up to twelve particles, we map out the changes in…

Soft Condensed Matter · Physics 2016-05-25 Frank Smallenburg , Hartmut Löwen

Significant transition strength in light $\alpha$-conjugate nuclei at low energy, typically below 10 MeV, has been observed in many experiments. In this work the isoscalar low-energy response of N=Z nuclei is explored using the Finite…

Nuclear Theory · Physics 2021-02-10 F. Mercier , A. Bjelčić , T. Nikšić , J. -P. Ebran , E. Khan , D. Vretenar

We present a force-biased Monte Carlo (FMC) method for structural modeling of transition metal clusters of Fe, Ni, and Cu with 5 to 60 atoms. By employing the Finnis-Sinclair potential for Fe and the Sutton-Chen potential for Ni and Cu, the…

Materials Science · Physics 2017-12-06 Dil K. Limbu , Parthapratim Biswas

We present a novel framework exploiting the cascade of phase transitions occurring during a simulated annealing of the Expectation-Maximisation algorithm to cluster datasets with multi-scale structures. Using the weighted local covariance,…

Machine Learning · Statistics 2021-01-13 T. Bonnaire , A. Decelle , N. Aghanim

Low-temperature (below 60K) phase changes of free clusters containing 50, 137, and 229 methane molecules have been observed in isoenergetic Molecular Dynamics computations. Bulk solid methane exhibits structural phase transformation at 20.4…

Atomic and Molecular Clusters · Physics 2007-05-23 E. Daykova , Ana Proykova

Computer simulations suggest that ultrathin metal wires should develop exotic, non-crystalline stable atomic structures, once their diameter decreases below a critical size of the order of a few atomic spacings. The new structures, whose…

Materials Science · Physics 2015-06-25 Oguz Gulseren , Furio Ercolessi , Erio Tosatti

Tight-binding molecular dynamics simulated annealing technique is employed to search for the ground state geometries of silicon clusters containing 11-17 atoms. These studies revealed that layer formation is the dominant growth pattern in…

chem-ph · Physics 2009-10-28 Atul Bahel , Jun Pan , Mushti V. Ramakrishna

The existence of shell structure and the accompanying high degeneracy of electronic levels leads to the possibility of strong superconducting pairing in metallic nanoclusters with N~100-1000 delocalized electrons. The most favorable cases…

Superconductivity · Physics 2009-11-11 Vladimir Z. Kresin , Yurii N. Ovchinnikov

We investigated the relative stability of the amorphous vs crystalline nanoparticles of size ranging between 0.8 and 1.8 nm. We found that, at variance from bulk systems, at low T small nanoparticles are amorphous and they undergo to an…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Sergio Orlandini , Simone Meloni , Luciano Colombo

The search for specific signals in ultra-relativistic heavy-light ion collisions addressing intrinsic geometric features of nuclei may open a new window to low energy nuclear structure. We discuss specifically the phenomenon of…

Nuclear Theory · Physics 2014-11-24 Enrique Ruiz Arriola , Wojciech Broniowski

We study the fraction $f$ of nucleotides involved in the formation of a cactus--like secondary structure of random heteropolymer RNA--like molecules. In the low--temperature limit we study this fraction as a function of the number $c$ of…

Genomics · Quantitative Biology 2013-05-30 O. V. Valba , M. V. Tamm , S. K. Nechaev

Charge transfer in collisions of Na_n^+ cluster ions with Cs atoms is investigated theoretically in the microscopic framework of non-adiabatic quantum molecular dynamics. The competing reaction channels and related processes affecting the…

Atomic and Molecular Clusters · Physics 2007-05-23 O. Knospe , J. Jellinek , U. Saalmann , R. Schmidt

We have performed large-scale Lennard-Jones molecular dynamics simulations of homogeneous vapor-to-liquid nucleation, with $10^9$ atoms. This large number allows us to resolve extremely low nucleation rates, and also provides excellent…

Chemical Physics · Physics 2014-04-07 Raymond Angélil , Jürg Diemand , Kyoko K. Tanaka , Hidekazu Tanaka

Results of molecular dynamics simulations of fission reactions $Na_{10}^{2+} \to Na_7^+ + Na_3^+$ and $Na_{18}^{2+} \to 2 Na_9^+$ are presented. Dependence of the fission barriers on isomer structure of the parent cluster is analyzed. It is…

Atomic and Molecular Clusters · Physics 2009-09-29 A. G. Lyalin , O. I. Obolensky , A. V. Solov'yov , Il A. Solov'yov , W. Greiner

Gold nanoclusters possess multiple competing structural motifs with small energy differences, enabling structural coexistence and interconversion. Using a high-accuracy machine learned potential trained on some 20'000 density functional…

The thermodynamics and kinetics of crystallization of nanoparticles, as opposed to bulk phases, may be influenced by surface and size effects. We investigate the importance of such factors in the crystallization process of gold, silver, and…

Statistical Mechanics · Physics 2024-07-09 Arthur France-Lanord , Sarath Menon , Julien Lam

Background: The sharp $1^-$ resonances with enhanced isoscalar dipole transition strengths are observed in many light nuclei at relatively small excitation energies, but their nature was unclear. Purpose: We show those resonances can be…

Nuclear Theory · Physics 2016-03-30 Y. Chiba , M. Kimura , Y. Taniguchi

We study the structures of the unstable Be isotopes with the theoretical method of antisymmetrized molecular dynamics. It is found that various structures of the excited states appear in the low-energy region of neutron-rich Be nuclei.…

Nuclear Theory · Physics 2009-11-07 Y. Kanada-En'yo , H. Horiuchi , A. Dote

Using pair potentials fitted to an ab--initio database, combined with replica--exchange simulated annealing, we show the complex, quasicrystal-related Al$_{11}$Ir$_4$ compound contains a new version of the "pseudo-Mackay" icosahedral…

Materials Science · Physics 2012-06-26 Marek Mihalkovič , C. L. Henley