Modeling Strategies for f-electron Materials
Abstract: Electronic structure theory is an essential tool in condensed mater research. It has been implemented in modeling tools such as quantum Monte Carlo, density functional theory (DFT), and tight-binding. It is widely used in modeling materials that span the periodic table. However, in materials where the lattice, charge, orbital, and spin degrees of freedom are strongly correlated, standard electronic structure theories fail. For heavier systems, f-electron materials especially, this is a significant disadvantage. There are several ways around these issues: we can include a Coulomb parameter for the electron interactions, use mean-field theory models to capture correlations and spectral properties, and we can reformulate the mathematics in terms of the Dirac equation to better understand relativistic effects. The challenge of accurately modeling the electronic behavior of actinides is one that has had significant attention from a small community of dedicated researchers due to its importance to quantum and nuclear materials science. I will discuss several tools and strategies for addressing electronic behavior in actinides, including planewave and all-electron DFT, mean field theory, and molecular dynamics as related to work on nuclear fuel design (UO2, UN, and UC), self-irradiation damage (metallic U and Pu), and possible future improvements to electronic theory approaches.
Bio: Roxanne Tutchton received a Ph.D. in Applied Physics from the Colorado School of Mines in 2017. She was a postdoctoral research associate at Los Alamos National Lab from 2018 to 2020, and transitioned to a staff scientist position in T-4 in 2020. Her background is in density functional theory (DFT), density functional perturbation theory (DFPT), and molecular dynamics (MD) calculation methods. As an early-career scientist at LANL she has led and collaborated on numerous projects involving modeling of strongly correlated systems including actinides, quantum materials, and materials under extreme conditions.
