Berlin 2012 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 15: Poster: New Instruments and Methods
CPP 15.13: Poster
Dienstag, 27. März 2012, 18:15–20:15, Poster A
The Interaction of Carbon Dioxide with Water Molecules: DFT-based Path-Metadynamics — •Grégoire Gallet1, Fabio Pietrucci1, and Wanda Andreoni1,2 — 1Centre Européen de Calcul Atomique et Moléculaire, École Polytechnique Fédérale de Lausanne, Switzerland — 2Institut de Théorie des Phénomènes Physiques, École Polytechnique Fédérale de Lausanne, Switzerland
We present an extensive study of the formation and dissociation of reactions CO2+nH2OH2CO3+(n−1)H2O in gas phase. We use both standard static approaches and path-metadynamics [1] to uncover the reaction mechanisms and to reconstruct the free energy surfaces. Our calculations are based on the pseudopotential/plane-wave implementation of the Kohn-Sham equations [2] and use several GGA and hybrid xc-functionals. Stringent validation tests of the computational methods were made and the performance of several xc-functionals was investigated. Excellent agreement was found among the different methods regarding the equilibrium and transition states configurations. Moreover, in spite of sizable differences in binding energies, all schemes agree in predicting the catalytic effect of water addition, also quantitatively. The role of entropy in determining the free energy barriers is critically investigated. [1] D. Branduardi, F.L. Gervasio and M. Parrinello; J. Chem. Phys., 126, 054103 (2007). [2] CPMD, www.cpmd.org; ©IBM Corp 1990-2012,©MPI für Festkörperforschung Stuttgart 1997-2001