Modeling of Thermodynamic and Diffusion Properties in Ionic Materials

Abstract

In this chapter, the modeling techniques of the thermodynamic and diffusion properties based on density functional theory in ionic materials, specifically oxide ceramic materials or ionic conductor materials are reviewed. Section 1 is the introduction of this book chapter. Section 2 is devoted to introduce the modeling methods of first-principles finite temperature thermodynamics, including quasi-harmonic phonon calculations and the Debye model. In the phonon model, the frozen phonon method, the linear response method, and the newly developed mixed-space method to model ionic polar materials are discussed. Section 3 introduces the general atomic diffusion theory, first-principles transition state calculations (double-well approach), and ab initio molecular dynamics simulations of the diffusion coefficients in ionic materials. Section 4 discusses some of the recent works of first-principles prediction of the thermodynamic and diffusion properties of ionic materials from our group and in the literature, with a focus on oxides for energy applications. Section 5 summarizes this book chapter.