| Autor: |
Ming-Liang Tan, Cendagorta, Joseph R., Ichiye, Toshiko |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 12/282014, Vol. 141 Issue 24, p1-7, 7p, 2 Color Photographs, 3 Graphs |
| Abstrakt: |
The most essential features of a water molecule that give rise to its unique properties are examined using computer simulations of different water models. The charge distribution of a water molecule characterized by molecular multipoles is quantitatively linked to the liquid properties of water via order parameters for the degree (S²) and symmetry (ΔS²) of the tetrahedral arrangement of the nearest neighbors, or "hydration shell." ΔS² also appears to determine the long-range tetrahedral network and interfacial structure. From the correlations, some models are shown to be unable to reproduce certain properties due to the limitations of the model itself rather than the parameterization, which indicates that they are lacking essential molecular features. Moreover, since these properties depend not only on S² but also on ΔS², the long-range structure in these models may be incorrect. Based on the molecular features found in the models that are best able to reproduce liquid properties, the most essential features of a water molecule in liquid water appear to be a charge distribution with a large dipole, a large quadrupole, and negative charge out of the molecular plane, as well as a symmetrically ordered tetrahedral hydration shell that results from this charge distribution. The implications for modeling water are also discussed. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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