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# John Rehr: Fast throughput calculations and the XAFS data base in the Materials Project

## 2020-May-11 @ 9:00 am - 10:00 am

Modern electronic structure theory and computational methods now permit efficient calculations of ground state properties, as exemplified by the tabulation of many-thousands of structures in the Materials Project [1]. Complementary advances in the theory of excited states have led to efficient methods for calculations of x-ray and electron spectroscopies, e.g., using the real-space Green’s multiple scattering theory in the FEFF9 code [2]. Here we discuss these developments and how they have been applied to high throughput calculations of x-ray absorption spectra in the Materials Project [3]. In particular, the world’s largest x-ray database has been constructed, which currently contains nearly 200,000 computed K-edge spectra for over 40,000 materials [4]. Recently this data base has been exploited using Machine-Learning techniques to accurately predict local coordination environments [5]. The database including the FEFF input and output files, is freely available from the Materials Project [1]. Extensions to L-edge and XAFS spectra are in progress.

References:
[1] A. Jain et al., The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1, 011002 (2013); https://www.materialsproject.org.
[2] John J. Rehr et al., Parameter-free calculations of X-ray spectra with FEFF9, Physical Chemistry Chemical Physics 12, 5503 (2010).
[3] K. Matthew, et al., High-throughput computational X-ray absorption spectroscopy, Scientific Data 5, 180151 (2018).
[4] Chen Zheng et al., Automated generation and ensemble-learned matching of X-ray absorption spectra, npj Computational Materials 4, 12 (2018).
[5] Chen Zheng et al., Random Forest Models for Accurate Identification of Coordination Environments from X-Ray Absorption Near-Edge Structure, Patterns 1, 100013 (2020).

## Details

Date:
2020-May-11
Time:
9:00 am - 10:00 am
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