Ab initio Molecular Dynamics for Determination of Structures of Alkali Metal Clusters and Their Temperatures Behavior; An Example of Li9+

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Title:Ab initio Molecular Dynamics for Determination of Structures of Alkali Metal Clusters and Their Temperatures Behavior; An Example of Li9+
Creators:
Bonačič-Koutecký, Vlasta
Reichardt, Detlef
Pittner, Jiří
Fantucci, Piercarlo
Koutecký, Jaroslav
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 63, 9, pp. 1431-1446
Uncontrolled Keywords:<i>Ab initio</i> calculations, <i>Ab initio</i> molecular dynamics, Lithium, Density functional, Alkali metal clusters

Abstract

It will be shown that an <i>ab initio</i> molecular dynamics procedure based on gradient corrected density functionals for exchange and correlation and using a Gaussian atomic basis (AIMD-GDF) implemented for parallel processing represents a suitable tool for detailed and accurate investigation of structural and dynamical properties of small systems. Gradients of the Born-Oppenheimer ground state energy, obtained by iterative solution of the Kohn-Sham equations, are used to calculate the forces acting on atoms at each instantaneous configuration along trajectories generated by solving classical equations of motion. Dynamics of different isomers of the Li<sub>9</sub><sup>+</sup> cluster have been investigated as a function of excess energy. It is shown that different isomers, even those similar in energy, can exhibit different structural and dynamical behavior. The analysis of the simulations leads to the conclusion that structures with a central atom, in particular the centered antiprism of Li<sub>9</sub><sup>+</sup> exhibit concerted mobility of the peripheral atoms at relatively low excess energy. In contrast, compact tetrahedral type structures show much more rigid behavior at low excess energy. However, the former ones need larger excess of internal energy to undergo isomerizations to geometrically different structures than the latter ones. At the time scale of our simulations we found that for the intermediate excess energies it is "easier" to carry the cluster in the basin of the lowest energy isomer than in the reverse direction. It has been found that the liquid-like behavior in small Li clusters becomes apparent at relatively high temperature in spite of large mobility of their atoms.

Title:Ab initio Molecular Dynamics for Determination of Structures of Alkali Metal Clusters and Their Temperatures Behavior; An Example of Li9+
Creators:
Bonačič-Koutecký, Vlasta
Reichardt, Detlef
Pittner, Jiří
Fantucci, Piercarlo
Koutecký, Jaroslav
Uncontrolled Keywords:<i>Ab initio</i> calculations, <i>Ab initio</i> molecular dynamics, Lithium, Density functional, Alkali metal clusters
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:63
Number:9
Page Range:pp. 1431-1446
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19981431UNSPECIFIED
ID Code:1391
Item Type:Article
Deposited On:06 Feb 2009 17:09
Last Modified:06 Feb 2009 16:09

Citation

Bonačič-Koutecký, Vlasta; Reichardt, Detlef; Pittner, Jiří; Fantucci, Piercarlo; Koutecký, Jaroslav (1998) Ab initio Molecular Dynamics for Determination of Structures of Alkali Metal Clusters and Their Temperatures Behavior; An Example of Li9+. Collection of Czechoslovak Chemical Communications, 63 (9). pp. 1431-1446. ISSN 0010-0765

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