The research objective of this award is to investigate the fundamental impact of crystal defects on material behavior through quantum-mechanical Density Functional Theory calculations. In particular, a seamless multiscale method that will enable the accurate study of defects at realistic concentrations is proposed. This method will be developed in the framework of a novel linear-scaling technique for Density Functional Theory, which traditionally has a cubic-scaling with respect to the number of atoms. Additionally, numerical coarse-graining approximations tailored to the nature of the defect will be utilized. The optimality of the overall formulation will be ensured through rigorous mathematical analysis. As an application, the proposed multiscale method will be used to study the effect of alloying on the strength and ductility of Magnesium with the goal of discovering novel alloys. Also, constitutive laws will be generated for dislocation dynamics simulations and, using these, the size-dependent strength observed during compression of nanopillars will be investigated.
If successful, the project will provide a breakthrough in bridging the electronic structure and continuum descriptions of crystal defects. This will significantly advance the current understanding of deformation and failure mechanisms in solids. Consequently, it will accelerate the discovery of novel materials with properties tailored to technological applications. As an example, new magnesium alloys with improved specific strength will have a noticeable impact on the transportation industry where there is a need for weight reduction without compromising structural integrity. Such alloys will help reduce fuel consumption, thereby also having a positive influence on the environment. The educational efforts of the project include broad dissemination of research results through social media and academic curriculum, creating a new website that documents the state of the art in crystal defect calculations, organizing conference symposia, and training graduate, undergraduate and high school students.
