Issue
EPL
Volume 82, Number 1, April 2008
Article Number 17001
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI http://dx.doi.org/10.1209/0295-5075/82/17001
Published online 04 March 2008
EPL, 82 (2008) 17001
DOI: 10.1209/0295-5075/82/17001

New fitting scheme to obtain effective potential from Car-Parrinello molecular-dynamics simulations: Application to silica

A. Carré1, 2, J. Horbach1, 3, S. Ispas2 and W. Kob2

1  Institut für Physik, Johannes Gutenberg-Universität Mainz - Staudinger Weg 7, 55099 Mainz, Germany
2  Laboratoire des Colloïdes, Verres et Nanomatériaux, Université Montpellier II and CNRS UMR 5587 34095 Montpellier, France
3  Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR) 51170 Köln, Germany

juergen.horbach@dlr.de

received 27 November 2007; accepted in final form 2 February 2008; published April 2008
published online 4 March 2008

Abstract
A fitting scheme is proposed to obtain effective potentials from Car-Parrinello molecular-dynamics (CPMD) simulations. It is used to parameterize a new pair potential for silica. MD simulations with this new potential are done to determine structural and dynamic properties and to compare these properties to those obtained from CPMD and a MD simulation using the so-called BKS potential. The new potential reproduces accurately the liquid structure generated by the CPMD trajectories, the experimental activation energies for the self-diffusion constants and the experimental density of amorphous silica. Also lattice parameters and elastic constants of $\alpha $-quartz are well reproduced, showing the transferability of the new potential.

PACS
71.15.Pd - Molecular dynamics calculations (Car-Parrinello) and other numerical simulations.
71.15.Mb - Density functional theory, local density approximation, gradient and other corrections.
61.20.Ja - Computer simulation of liquid structure.

© EPLA 2008