Structural relaxation in supercooled orthoterphenyl

Abstract

We report molecular-dynamics simulation results performed for a model of molecular liquid orthoterphenyl in supercooled states, which we then compare with both experimental data and mode-coupling-theory (MCT) predictions, aiming at a better understanding of structural relaxation in orthoterphenyl. We pay special attention to the wavenumber dependence of the collective dynamics. It is shown that the simulation results for the model share many features with experimental data for real system, and that MCT captures the simulation results at the semiquantitative level except for intermediate wavenumbers connected to the overall size of the molecule. Theoretical results at the intermediate wavenumber region are found to be improved by taking into account the spatial correlation of the molecule's geometrical center. This supports the idea that unusual dynamical properties at the intermediate wavenumbers, reported previously in simulation studies for the model and discernible in coherent neutron-scattering experimental data, are basically due to the coupling of the rotational motion to the geometrical-center dynamics. However, there still remain qualitative as well as quantitative discrepancies between theoretical prediction and corresponding simulation results at the intermediate wavenumbers, which call for further theoretical investigation.

15 pages, 12 figures, Phys. Rev. E in press

References in corpus (28)

• Testing Mode-Coupling Theory for a Supercooled Binary Lennard-Jones Mixture II: Intermediate Scattering Function and Dynamic Susceptibility
• Neutron Scattering Studies of the Model Glass Former Ortho-terphenyl
• A quantitative test of the mode-coupling theory of the ideal glass transition for a binary Lennard-Jones system
• Supercooled Water and the Kinetic Glass Transition II: Collective Dynamics
• Ideal glass transitions for hard ellipsoids
• The Debye-Waller factor of liquid silica: Theory and simulation
• The relaxation dynamics of a viscous silica melt: II The intermediate scattering functions
• Dynamics and Configurational Entropy in the LW Model for Supercooled Orthoterphenyl
• Alpha-Relaxation Processes in Binary Hard-Sphere Mixtures
• Investigating the influence of different thermodynamic paths on the structural relaxation in a glass forming polymer melt
• Fast relaxation in a fragile liquid under pressure
• Idealized glass transitions for a system of dumbbell molecules
• Molecular mode-coupling theory for supercooled liquids: Application to water
• Molecular dynamics simulation of the fragile glass former ortho-terphenyl: a flexible molecule model
• A mode-coupling theory for the glassy dynamics of a diatomic probe molecule immersed in a simple liquid
• Quantitative tests of mode-coupling theory for fragile and strong glass-formers
• Reorientational relaxation of a linear probe molecule in a simple glassy liquid
• Structural relaxation in a system of dumbbell molecules
• Completely monotone solutions of the mode-coupling theory for mixtures
• Dynamics in a supercooled molecular liquid: Theory and Simulations
• Molecular mode-coupling theory applied to a liquid of diatomic molecules
• Wavenumber dependence of structural alpha relaxation in a molecular liquid
• Microscopic dynamics of molecular liquids and glasses: Role of orientations and translation-rotation coupling
• Molecular dynamics simulation of the fragile glass former ortho-terphenyl: a flexible molecule model. II. Collective dynamics
• The mean-squared displacement of a molecule moving in a glassy system
• Neutron scattering and molecular correlations in a supercooled liquid
• Nonergodicity parameters for a molecular liquid: A comparison between mode coupling theory and simulation
• Structural relaxation in a supercooled molecular liquid

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• Relaxation Scenarios in a Mixture of Large and Small Spheres: Dependence on the Size Disparity
• Slow Dynamics in Ion-Conducting Sodium Silicate Melts: Simulation and Mode-Coupling Theory
• Structural and conformational dynamics of supercooled polymer melts: Insights from first-principles theory and simulations
• Dynamics in a supercooled liquid of symmetric dumbbells: Reorientational hopping for small molecular elongations
• A spherical model with directional interactions: I. Static properties
• From caging to Rouse dynamics in polymer melts with intramolecular barriers: a critical test of the Mode Coupling Theory
• Onset of slow dynamics in difluorotetrachloroethane glassy crystal
• Atomic motions in the $\alpha \beta$-region of glass-forming polymers: Molecular versus Mode Coupling Theory approach
• Crystallization of the Lewis-Wahnström ortho-terphenyl model
• Glassy dynamics of a binary Voronoi fluid: A mode-coupling analysis
• Statistical Mechanics of Glass Formation in Molecular Liquids with OTP as an Example