EAIFR is pleased to welcome a distinguished condensed matter physicist for an online seminar on 11 February, 2021. Speaking at 16:00 (GMT+2), David Prendergast of The Molecular Foundry at the Berkeley Lab, USA will speak on "X-ray Spectroscopy as a Probe of Electronic Structure."

All are welcome: please pre-register here.

Prendergast is a Senior Staff Scientist and Facility Director for Theory of Nanostructured Materials at the Molecular Foundry, a Department of Energy Nanoscale Science Research Center, at Lawrence Berkeley National Laboratory. He has developed a remarkably broad multidisciplinary research program, involving X-ray science at the Advanced Light Source, and spanning chemical and materials sciences. David's research combines first-principles electronic structure theory and molecular dynamics simulations to study energy-relevant processes in complex materials systems at the nanoscale, especially at interfaces, often through direct simulation and interpretation of X-ray spectroscopy experiments.

Abstract: X-ray spectroscopy is a widely used tool to explore the properties of matter by inducing excitations using high energy photons – typically with hundreds or thousands of electron volts. From the perspective of electronic structure, it provides access to the nominally inert inner-shell or core electrons of atoms and uses their strong localization to reveal the local electronic properties of the excited atom defined in part by its surroundings – in a molecule, a crystal, a molecular liquid, etc. As such, X-ray spectroscopy is an excellent means of validating electronic structure theory. In this talk, I will describe how one can begin to simulate X-ray spectroscopy using density functional theory (DFT). Surprisingly, this ground-state, mean-field theory can accurately describe excitations of inner-shell electrons, provided that we apply an intuitive approach that leverages its strengths. We will focus primarily on excitations of 1s electrons (so-called K-edge spectroscopy) and X-ray absorption. We will also briefly discuss the potential for expanding this research in many appealing directions (ultrafast science, quantum materials, batteries, etc). Ultimately, you should understand how your own (relatively) simple electronic structure calculations can support or define cutting-edge measurements across the world.