**About this Abstract** |

**Meeting** |
**2018 TMS Annual Meeting & Exhibition
** |

**Symposium
** |
**Hume-Rothery Award Symposium: Computational Thermodynamics and Its Implications to Kinetics, Properties, and Materials Design
** |

**Presentation Title** |
Diffusion Coefficients of Alloying Elements in Dilute Mg Alloys from First-principles: A Comparative Study of 8-frequency Model, 13-frequency Model, and Kinetic Monte Carlo |

**Author(s)** |
Bi-Cheng Zhou, Irina Belova, Shun-Li Shang, Yi Wang, Graeme Murch, Zi-Kui Liu |

**On-Site Speaker (Planned)** |
Bi-Cheng Zhou |

**Abstract Scope** |
First-principles calculations based on density functional theory have been used to predict the temperature-dependent dilute solute diffusion coefficients of 61 alloying elements in hcp Mg. Solute migration minimum energy pathways were calculated using climbing image nudged elastic band method and atomic jumping frequencies were subsequently obtained with harmonic transition state theory. Vibrational properties were calculated with the quasi-harmonic Debye model. PBEsol exchange correlation potential was used to obtain accurate vacancy formation energy as well as vibrational properties. It is found that early rare earth elements and large solutes (Ca, Sr etc.) have lower direct migration barriers and exhibit strong correlation effects. Three computational methods: 8-frequency model, 13-frequency model, and kinetic Monte Carlo simulations were used to calculate the tracer correlation factors for solutes with strong correlation. Excellent agreement between the calculated diffusion coefficients and available experiments in the literature was obtained. |

**Proceedings Inclusion?** |
Planned: Supplemental Proceedings volume |