Ab initio investigation of the topology and properties of three-dimensional clusters of water (H2O)(n).
Fiche publication
Date publication
février 2008
Auteurs
Membres identifiés du Cancéropôle Est :
Pr DAUCHEZ Manuel, Pr MARTINY Laurent
Tous les auteurs :
Sediki A, Lebsir F, Martiny L, Dauchez M, Krallafa A
Lien Pubmed
Résumé
Quantum mechanical studies were carried out in order to understand and describe the nature and strength of the hydrogen bond topology in three dimensional water cluster systems (H2O),,, in the size range 6-20 molecules. Optimal structures and vibrational frequencies of cage like water clusters are computed at the Hartree-Fock (1417) and the electronic density functional theory (DFT) level of theory with a detailed data analysis. Theoretical results are compared to experimental data when available. The general tendency is a decrease of the global minimum energy as the cluster size increases. The nearest neighbour separation between oxygen atoms decreases exponentially when the cluster size increases. The present work suggests that DFT results are in a good agreement with the corresponding HF data, however slight differences remain with regard to values of the nearest neighbour separation between oxygen atoms. The Morokuma's decomposition of the total interaction energy performed on two and three-dimensional clusters lead to a better understanding of the cluster formation with a strong polarization energy component. (c) 2007 Elsevier Ltd. All rights reserved.
Référence
Food Chem. 2008 Feb 15;106(4):1476-84.