Simulated field-modulated x-ray absorption in titania

Pragathi Darapaneni; Alexander M Meyer; Mykola Sereda; Adam Bruner; James A Dorman; Kenneth Lopata

doi:10.1063/5.0009677

Simulated field-modulated x-ray absorption in titania

J Chem Phys. 2020 Aug 7;153(5):054110. doi: 10.1063/5.0009677.

Authors

Pragathi Darapaneni¹, Alexander M Meyer², Mykola Sereda², Adam Bruner², James A Dorman¹, Kenneth Lopata²

Affiliations

¹ Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
² Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, USA.

PMID: 32770877
DOI: 10.1063/5.0009677

Abstract

In this paper, we present a method to compute the x-ray absorption near-edge structure (XANES) spectra of solid-state transition metal oxides using real-time time-dependent density functional theory, including spin-orbit coupling effects. This was performed on bulk-mimicking anatase titania (TiO₂) clusters, which allows for the use of hybrid functionals and atom-centered all electron basis sets. Furthermore, this method was employed to calculate the shifts in the XANES spectra of the Ti L-edge in the presence of applied electric fields to understand how external fields can modify the electronic structure, and how this can be probed using x-ray absorption spectroscopy. Specifically, the onset of t_2g peaks in the Ti L-edge was observed to red shift and the e_g peaks were observed to blue shift with increasing fields, attributed to changes in the hybridization of the conduction band (3d) orbitals.