Improving the predictive quality of time-dependent density functional theory calculations of the X-ray emission spectroscopy of organic molecules

© 2020 The Authors. Journal of Computational Chemistry published by Wiley Periodicals, Inc.

Bibliographische Detailangaben
Veröffentlicht in:Journal of computational chemistry. - 1984. - 41(2020), 11 vom: 30. Apr., Seite 1081-1090
1. Verfasser: Fouda, Adam A E (VerfasserIn)
Weitere Verfasser: Besley, Nicholas A
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2020
Zugriff auf das übergeordnete Werk:Journal of computational chemistry
Schlagworte:Journal Article TDDFT X-ray emission spectroscopy XES organic molecules
Beschreibung
Zusammenfassung:© 2020 The Authors. Journal of Computational Chemistry published by Wiley Periodicals, Inc.
The simulation of X-ray emission spectra of organic molecules using time-dependent density functional theory (TDDFT) is explored. TDDFT calculations using standard hybrid exchange-correlation functionals in conjunction with large basis sets can predict accurate X-ray emission spectra provided an energy shift is applied to align the spectra with experiment. The relaxation of the orbitals in the intermediate state is an important factor, and neglect of this relaxation leads to considerably poorer predicted spectra. A short-range corrected functional is found to give emission energies that required a relatively small energy shift to align with experiment. However, increasing the amount of Hartree-Fock exchange in this functional to remove the need for any energy shift led to a deterioration in the quality of the calculated spectral profile. To predict accurate spectra without reference to experimental measurements, we use the CAM-B3LYP functional with the energy scale determined with reference to a Δself-consistent field calculation for the highest energy emission transition
Beschreibung:Date Revised 23.03.2020
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1096-987X
DOI:10.1002/jcc.26153