Phase behaviour of empirical potentials of titanium dioxide
arXiv:1908.03497 · doi:10.1063/1.5115161
Abstract
In recent years, several relatively similar empirical models of titanium dioxide have been proposed as reparameterisations of the potential of Matsui and Akaogi, with the Buckingham interaction replaced by a Lennard-Jones interaction. However, because of the steepness of the repulsive region of the Lennard-Jones potential, such reparameterised models result in rather different mechanical and thermodynamic properties compared to the original potential. Here, we use free-energy calculations based on the Einstein crystal method to compute the phase diagram of both the Matsui-Akaogi potential and one of its Lennard-Jones-based reparameterisations. Both potentials are able to support a large number of distinct crystalline polymorphs of titanium dioxide that have been observed in experiment, but the regions of thermodynamic stability of the individual phases are significantly different from one another. Moreover, neither potential results in phase behaviour that is fully consistent with the available experimental evidence.
References in corpus (9)
- Canonical sampling through velocity-rescaling
- What ice can teach us about water interactions: a critical comparison of the performance of different water models
- Ab initio thermodynamics of liquid and solid water
- Determination of phase diagrams via computer simulation: Methodology and applications to water, electrolytes and proteins
- The stability, electronic structure, and optical property of TiO2 polymorphs
- Phase Stability of TiO Polymorphs from Diffusion Quantum Monte Carlo
- Quantum Monte Carlo study of the energetics of the rutile, anatase, brookite, and columbite TiO polymorphs
- Free energy calculations for atomic solids through the Einstein crystal/molecule methodology using GROMACS and LAMMPS
- Unusual Compression Behavior of Columbite TiO2 via First-Principles Calculations