Dresden 2006 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 21: Statistical Physics (general) I
DY 21.3: Vortrag
Dienstag, 28. März 2006, 10:30–10:45, SCH 251
Size effects in molecular dynamics simulations of nucleation — •Jan Wedekind1, David Reguera2, and Reinhard Strey1 — 1Institut für Physikalische Chemie, Universität zu Köln, Luxemburger Str. 116, D-50939 Köln, Germany — 2Universitat de Barcelona, Departament de Física Fonamental, Facultat de Física, Universitat de Barcelona, Martí i Franquès, 1, 08028-Barcelona, Spain
Most molecular dynamics (MD) simulations of vapor-liquid nucleation are performed in a closed, canonical NVT-system. Under these conditions the vapor pressure and thus the supersaturation change during the condensation and growth of a droplet due to the fixed total number of molecules N. Furthermore, the feasibility of observing a nucleation event may depend significantly on the size of the system at hand. We investigate the potential importance of finite size effects in MD simulations of nucleation in the framework of the modified liquid drop model (MLD) [1,2] and the implications of our investigations on the results reported in the literature. Furthermore we show with comparatively simple calculations how it is possible to estimate the system size in terms of N or similarly V, beyond which corrections due to size effects become negligible. By optimizing the system parameters it is possible to save valuable calculation time and extend the range of supersaturations attainable by simulations by several orders of magnitude.
[1] C. L. Weakliem and H. Reiss, J. Chem. Phys. 99 (7), 5374 (1993).
[2] D. Reguera, R. K. Bowles, Y. Dijkaev, and H. Reiss, J. Chem. Phys. 118 (1), 340 (2003).