Non-linear effects in core photoemission from Real-time TDDFT.
ORAL
Abstract
In core photoemission spectroscopy a photon is absorbed and a core electron is emitted into the continuum, leaving behind a core hole. The remainder of the system responds to screen the core hole, significantly affecting the spectrum. State-of-the-art many-body perturbation theory (MBPT) methods such as the GW and the cumulant expansion are usually evaluated in the linear-response approximation. This requires a weak core hole; if this is not the case, one needs to go beyond linear response. This can be carried out with a non-linear cumulant derived in a MBPT framework, and evaluated from a real-time time-dependent density functional theory (TDDFT) approach. We discuss the application of this method with calculations carried out with an extension of our RT-Siesta code [1] for systems with d- and f valence electrons.
[1] J. J. Kas, F. D. Vila, J. J. Rehr, and S. A. Chambers, Phys. Rev. B. 91, 121112(R) (2015).
[1] J. J. Kas, F. D. Vila, J. J. Rehr, and S. A. Chambers, Phys. Rev. B. 91, 121112(R) (2015).
*This work was supported by the ERC grant SEED, and as part of the Computational Chemical Sciences Program funded by the U.S. Department of Energy, Office of Science, BES, Chemical Sciences, Geosciences and Biosciences Division in the Center for Scalable and Predictive methods for Excitations and Correlated phenomena (SPEC) at PNNL, and with computer support from DOE-NERSC.
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Presenters
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Marilena Tzavala
- Physics, University of Washington