Comparative classical and ab initio Molecular Dynamics study of molten and glassy germanium dioxide
arXiv:0804.2654 · doi:10.1088/0953-8984/20/28/285106
Abstract
A Molecular Dynamics (MD) study of static and dynamic properties of molten and glassy germanium dioxide is presented. The interactions between the atoms are modelled by the classical pair potential proposed by Oeffner and Elliott (OE) [Oeffner R D and Elliott S R 1998, Phys. Rev. B, 58, 14791]. We compare our results to experiments and previous simulations. In addition, an ab initio method, the so-called Car-Parrinello Molecular Dynamics (CPMD), is applied to check the accuracy of the structural properties, as obtained by the classical MD simulations with the OE potential. As in a similar study for SiO2, the structure predicted by CPMD is only slightly softer than that resulting from the classical MD. In contrast to earlier simulations, both the static structure and dynamic properties are in very good agreement with pertinent experimental data. MD simulations with the OE potential are also used to study the relaxation dynamics. As previously found for SiO2, for high temperatures the dynamics of molten GeO2 is compatible with a description in terms of mode coupling theory.
27 pages, 16 figures
References in corpus (23)
- Separable Dual Space Gaussian Pseudo-potentials
- Cooling rate effects in amorphous Silica: A Computer Simulation Study
- An Efficient and Accurate Car-Parrinello-like Approach to Born-Oppenheimer Molecular Dynamics
- Static and Dynamic Properties of a Viscous Silica Melt Molecular Dynamics Computer Simulations
- Capillary Rise in Nanopores: Molecular Dynamics Evidence for the Lucas-Washburn Equation
- Molecular structural order and anomalies in liquid silica
- Computer simulations of liquid silica: equation of state and liquid-liquid phase transition
- Excitation lines and the breakdown of Stokes-Einstein relations in supercooled liquids
- On nonlinear susceptibility in supercooled liquids
- Length scale for the onset of Fickian diffusion in supercooled liquids
- Some Finite Size Effects in Simulations of Glass Dynamics
- High Frequency Dynamics of Amorphous Silica
- Structural properties of molten silicates from ab initio molecular-dynamics simulations: comparison between CaO-AlO-SiO and SiO
- The Debye-Waller factor of liquid silica: Theory and simulation
- Spatially heterogeneous dynamics and dynamic facilitation in a model of viscous silica
- The relaxation dynamics of a viscous silica melt: II The intermediate scattering functions
- Critical fluctuations and breakdown of Stokes-Einstein relation in the Mode-Coupling Theory of glasses
- Water adsorption on amorphous silica surfaces: A Car-Parrinello simulation study
- Classical and ab initio molecular dynamic simulation of an amorphous silica surface
- Time scale for the onset of Fickian diffusion in supercooled liquids
- The Dynamics of Supercooled Silica: Acoustic modes and Boson peak
- Computer investigation of the energy landscape of amorphous silica
- Droplets and the configurational entropy crisis for random first order transitions