Materials Theory

We use state-of-the-art theory to advance understanding of complex materials. The emphasis is on gaining microscopic atomic level understanding of materials properties within the rich backdrop provided by ORNL experimental efforts. Theory impacts the overall program through prediction of novel phenomena, interpretation of results, prediction of materials with enhanced properties, and definition of critical experiments. Methods that include van der Waals interactions are used to understand the properties of materials with important dispersion interactions. We identify the atomistic and electronic underpinnings of structural and mechanical properties of advanced alloys, intermetallics and ceramics. This is leading to update understanding of long-standing scientific problems. These include (1) the formation and stability of specific nanoclusters in oxide dispersion strengthened alloys and prediction of update nanostructured alloys, (2) chemical bonding and properties of novel high pressure phases, and (3) development of sufficiently accurate metal-H/He potentials for reliable, predictive molecular dynamics studies of defect/dislocation interactions. We use first principles and first principles-based theories to unravel chemical and structural underpinnings of properties, including superconductivity, magnetism, ferroelectricity, and transport. Particular emphasis is on elucidating the fundamental origins of complex behavior observed in novel materials under experimental investigation at ORNL.