The effect of basis set and exchange-correlation functional on time-dependent density functional theory calculations within the Tamm-Dancoff approximation of the X-ray emission spectroscopy of transition metal complexes

Roper, Ian P.E.; Besley, Nicholas A.

Abstract

The simulation of X-ray emission spectra of transition metal complexes with time- dependent density functional theory (TDDFT) is investigated. X-ray emission spectra can be computed within TDDFT in conjunction with the Tamm-Dancoff approximation by using a reference determinant with a vacancy in the relevant core orbital, and these calculations can be performed using the frozen orbital approxi- mation or with the relaxation of the orbitals of the intermediate core-ionised state included. Both standard exchange-correlation functionals and functionals specifically designed for X-ray emission spectroscopy are studied, and it is shown that the computed spectral band profiles are sensitive to the exchange-correlation functional used. The computed intensities of the spectral bands can be rationalised by consid- ering the metal p orbital character of the valence molecular orbitals. To compute X-ray emission spectra with the correct energy scale allowing a direct comparison with experiment requires the relaxation of the core-ionised state to be included and the use of specifically designed functionals with increased amounts of Hartree-Fock exchange in conjunction with high quality basis sets. A range-corrected functional with increased Hartree-Fock exchange in the short range provides transition energies close to experiment and spectral band profiles that have a similar accuracy to those from standard functionals.

Citation

Roper, I. P., & Besley, N. A. (in press). The effect of basis set and exchange-correlation functional on time-dependent density functional theory calculations within the Tamm-Dancoff approximation of the X-ray emission spectroscopy of transition metal complexes. Journal of Chemical Physics, 144, Article 114104. https://doi.org/10.1063/1.4943862

• Journal Article Type: Article
• Acceptance Date: Mar 1, 2016
• Online Publication Date: Mar 16, 2016
• Deposit Date: Mar 2, 2016
• Publicly Available Date: Mar 16, 2016
• Journal: Journal of Chemical Physics
• Print ISSN: 0021-9606
• Electronic ISSN: 1089-7690
• Publisher: American Institute of Physics
• Peer Reviewed: Peer Reviewed
• Volume: 144
• Article Number: 114104
• DOI: https://doi.org/10.1063/1.4943862
• Keywords: TDDFT, X-ray emission spectroscopy
• Public URL: https://nottingham-repository.worktribe.com/output/780169
• Publisher URL: http://scitation.aip.org/content/aip/journal/jcp/144/11/10.1063/1.4943862
• Related Public URLs: http://scitation.aip.org/content/aip/journal/jcp
• Additional Information: Copyright 2016 AIP Publishing. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing.; The following article has been submitted to/accepted by Journal of Chemical Physics. After it is published, it will be found at http://scitation.aip.org/content/aip/journal/jcp
• Contract Date: Mar 2, 2016