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Two- and N-step correlated models for the analysis of molecular dynamics trajectories of linear molecules in silicalite

Demontis, Pierfranco and Suffritti, Giuseppe Baldovino and Tilocca, Antonio (2000) Two- and N-step correlated models for the analysis of molecular dynamics trajectories of linear molecules in silicalite. The Journal of Chemical Physics, Vol. 113 (17), p. 7588-7592. eISSN 1089-7690. Article.

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DOI: 10.1063/1.1312867

Abstract

Recent molecular dynamics data on the diffusion of linear diatomic and triatomic molecules in the zeolite silicalite are analyzed in terms of a new correlated model [F. Jousse, S. M. Auerbach, and D. P. Vercauteren, J. Chem. Phys. 112, 1531 (2000)] capable to account for both first- and higher-order correlation effects. This "N-step" model reproduces very well our calculated mean square displacements and diffusion coefficients of the molecules considered. The improvements with respect to the results obtained with our previous "two-step" model [P. Demontis, J. Kärger, G. B. Suffritti, and A. Tilocca, Phys. Chem. Chem. Phys. 2, 1455 (2000)] are remarkable for all molecules except chlorine, showing that only in this case the effect of (negative) correlations spanning more than two jumps between channel intersections (~20 Å) can be neglected. The basic trajectory analysis in terms of single- and two-step models, besides being an useful reference, provides all the input data needed for the application of the N-step model. Indeed, in its silicalite formulation, the N-step model is strongly linked to the two-step one because it calculates the probability of a sequence of jumps in the same channel by means of the correlations between any two consecutive jumps. Finally, the possibility to obtain qualitative insight into the diffusive mechanism through various kind of correlation coefficients is discussed.

Item Type:Article
ID Code:326
Status:Published
Refereed:Yes
Uncontrolled Keywords:Molecular dynamics method, diffusion, minerals
Subjects:Area 03 - Scienze chimiche > CHIM/02 Chimica fisica
Divisions:001 Università di Sassari > 01 Dipartimenti > Chimica
Publisher:American Institute of Physics
eISSN:1089-7690
Publisher Policy:Depositato in conformità con la politica di copyright dell'Editore
Deposited On:18 Aug 2009 10:02

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