Metabasin dynamics and local structure in supercooled water

• Autores: Rodriguez Fris, Jorge Ariel; Appignanesi, Gustavo Adrian; La Nave, Emilia; Sciortino, Francesco
• Año de publicación: 2007
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: SUPERCOOLED WATER; ENERGY LANDSCAPE; DYNAMICAL HETEROGENEITIES; GLASS TRANSITION
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

We employ the distance matrix method to investigate metabasin dynamics in supercooled water. We find that the motion of the system consists in the exploration of a finite region of configuration space enclosing several distinct local minima, named metabasin, followed by a sharp crossing to a different metabasin. The characteristic time between metabasin transitions is comparable to the structural relaxation time, suggesting that these transitions are relevant for the long-time dynamics. The crossing between metabasins is accompanied by very rapid diffusional jumps of several groups of dynamically correlated particles. These particles form relatively compact clusters and act as cooperative relaxing units responsible for the density relaxation. We find that these mobile particles are often characterized by an average coordination larger than four, i.e., they are located in regions where the tetrahedral hydrogen bond network is distorted. distinct local minima, named metabasin, followed by a sharp crossing to a different metabasin. The characteristic time between metabasin transitions is comparable to the structural relaxation time, suggesting that these transitions are relevant for the long-time dynamics. The crossing between metabasins is accompanied by very rapid diffusional jumps of several groups of dynamically correlated particles. These particles form relatively compact clusters and act as cooperative relaxing units responsible for the density relaxation. We find that these mobile particles are often characterized by an average coordination larger than four, i.e., they are located in regions where the tetrahedral hydrogen bond network is distorted. enclosing several distinct local minima, named metabasin, followed by a sharp crossing to a different metabasin. The characteristic time between metabasin transitions is comparable to the structural relaxation time, suggesting that these transitions are relevant for the long-time dynamics. The crossing between metabasins is accompanied by very rapid diffusional jumps of several groups of dynamically correlated particles. These particles form relatively compact clusters and act as cooperative relaxing units responsible for the density relaxation. We find that these mobile particles are often characterized by an average coordination larger than four, i.e., they are located in regions where the tetrahedral hydrogen bond network is distorted.
Fil: Rodriguez Fris, Jorge Ariel. Universidad Nacional del Sur. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina
Fil: Appignanesi, Gustavo Adrian. Universidad Nacional del Sur. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina
Fil: La Nave, Emilia. Centre National de la Recherche Scientifique; Francia
Fil: Sciortino, Francesco. Centre National de la Recherche Scientifique; Francia