• Fritsch, D.: Chapter 10 : Crystallographic diffraction techniques and density functional theory: two sides of the same coin? In: edited by Susan Schorr, Claudia Weidenthaler [Ed.] : Crystallography in Materials Science From Structure - Property Relationships to EngineeringBerlin ; Boston: De Gruyter, 2021. - ISBN 978-3-11-067485-9, p. 317-338


Abstract:
Over the last decades, materials science has developed into an independent research area of science and engineering, thereby merging elements of disciplines such as solid-state physics, chemistry, and crystallography. With the advent of density functional theory and the widespread availability of high-performance computing facilities, computational materials science emerged as a particularly important subfield. Materials science pursues the improvement of already known and the design and discovery of new materials to be utilized in current and future technological applications, ideally taking into account their environmental impact and sustainability. One prominent way to influence material properties uses substitutional and/or occupational disorder, as in solid solutions of different materials or controlled changes in defect concentrations. The accurate investigation of substitutional and/or occupational disorder with experimental and theoretical methods poses fundamentally different problems. On the one hand, experimental diffraction techniques usually employed in crystallography, provide only averaged information of material properties and require additional experimental techniques to explore local disorder. On the other hand, commonly applied periodic boundary conditions within density functional theory (DFT) require the application of supercells to describe substitutional and/or occupational disorder. In a way, diffraction techniques and DFT can be viewed as a top-down and bottom-up approach to materials science investigations. This chapter presents recent advances in the investigation of structure–property relations from bottom-up approaches (DFT) with a particular focus on functional energy materials. Advantages, disadvantages, and limitations of this method will be discussed and how the investigation of material properties can be supplemented by top-down approaches (diffraction techniques) usually applied in crystallography.