TY - JOUR

T1 - Structural relaxation in a system of dumbbell molecules

AU - Chong, S. H.

AU - Götze, W.

PY - 2002/5

Y1 - 2002/5

N2 - The interaction-site-density-fluctuation correlators, the dipole-relaxation functions, and the mean-squared displacements of a system of symmetric dumbbells of fused hard spheres are calculated for two representative elongations of the molecules within the mode-coupling theory for the evolution of glassy dynamics. For large elongations, universal relaxation laws for states near the glass transition are valid for parameters and time intervals similar to the ones found for the hard-sphere system. Rotation-translation coupling leads to an enlarged crossover interval for the mean-squared displacement of the constituent atoms between the end of the von Schweidler regime and the beginning of the diffusion process. For small elongations, the superposition principle for the reorientational α process is violated for parameters and time intervals of interest for data analysis, and there is a strong breaking of the coupling of the α-relaxation scale for the diffusion process with that for representative density fluctuations and for dipole reorientations.

AB - The interaction-site-density-fluctuation correlators, the dipole-relaxation functions, and the mean-squared displacements of a system of symmetric dumbbells of fused hard spheres are calculated for two representative elongations of the molecules within the mode-coupling theory for the evolution of glassy dynamics. For large elongations, universal relaxation laws for states near the glass transition are valid for parameters and time intervals similar to the ones found for the hard-sphere system. Rotation-translation coupling leads to an enlarged crossover interval for the mean-squared displacement of the constituent atoms between the end of the von Schweidler regime and the beginning of the diffusion process. For small elongations, the superposition principle for the reorientational α process is violated for parameters and time intervals of interest for data analysis, and there is a strong breaking of the coupling of the α-relaxation scale for the diffusion process with that for representative density fluctuations and for dipole reorientations.

UR - http://www.scopus.com/inward/record.url?scp=41349104452&partnerID=8YFLogxK

U2 - 10.1103/PhysRevE.65.051201

DO - 10.1103/PhysRevE.65.051201

M3 - Article

AN - SCOPUS:41349104452

SN - 1539-3755

VL - 65

SP - 051201/1-051201/14

JO - Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics

JF - Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics

IS - 5

M1 - 051201

ER -