Water at supercritical conditions: A first principles study

Autor:	Kiyoyuki Terakura, Michele Parrinello, Chee Chin Liew, Mauro Boero, Tamio Ikeshoji
Rok vydání:	2001
Předmět:	Hydrogen Hydrogen bond Critical phenomena General Physics and Astronomy chemistry.chemical_element Dielectric Supercritical fluid Dipole Crystallography Molecular dynamics chemistry Critical point (thermodynamics) Chemical physics Physical and Theoretical Chemistry
Zdroj:	The Journal of Chemical Physics. 115:2219-2227
ISSN:	1089-7690 0021-9606
Popis:	We analyze, via first principles molecular dynamics, the structural and electronic properties of water close to and above the critical point. Contrary to the ordinary liquid state, at supercritical conditions the hydrogen bond network is destabilized to various extents and the continuous breaking and reformation of hydrogen bonded structures allow large density and dipole fluctuations that, in turn, can significantly affect the dielectric properties of the solvent. Close to the critical point, where the density is very low, small clusters, mainly dimers and trimers, are the dominant features, but many molecules exhibit no H-bond. On the other hand, at higher densities, more extended structures appear, but still a continuous network cannot form. In both cases, H-bond configurations that are anomalous with respect to the normal liquid phase appear. These features strongly affect the solvent properties of supercritical water with respect to those of ambient water. They most likely vary continuously as a func...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::cab8dbe88aa57d41d8d2cb160a193152 https://doi.org/10.1063/1.1379767 Zobrazit plný text záznamu