Time-dependent density functional theory calculations of near-edge X-ray absorption fine structure with short-range corrected functionals

Nicholas A. Besley, Michael J. G. Peach, David J. Tozer, Phys. Chem. Chem. Phys., 11, 10350–10358, 2009.


In my first collaboration with Dr Nicholas Besley, of the University of Nottingham, we investigated the description of near-edge X-ray absorption spectra. In these challenging systems, conventional Coulomb-attenuated functionals such as CAM-B3LYP are not competitive with fixed hybrid functionals that contain large amounts of exact exchange. This is due to the need for short-range exact orbital exchange (functionals such as CAM-B3LYP contain only increased amounts of long-range exact exchange). We developed a series of functionals that contain large amounts of short-range exact exchange, and small amounts of long-range exact exchange, which are able to accurately describe the X-ray absorption spectra. The study also emphasises the difficulty in obtaining functionals that can accurately describe all categories of excitation.

Further information, including details of subsequent work in this area, can be found on the research page. For the abstract, and access to the full text, see below.


We report calculations of core excitation energies and near-edge X-ray absorption fine structure (NEXAFS) spectra computed with time-dependent density functional theory (TDDFT). TDDFT with generalized gradient approximation and standard hybrid exchange–correlation functionals is known to underestimate core excitation energies. This failure is shown to be associated with the self-interaction error at short interelectronic distances. Short-range corrected hybrid functionals are shown to reduce the error in the computed core excitation energies for first and second row nuclei in a range of molecules to a level approaching that observed in more traditional excited states calculations in the ultraviolet region. NEXAFS spectra computed with the new functionals agree well with experiment and the pre-edge features in the NEXAFSspectra of plastocyanin are correctly predicted.

Leave a Comment

Your email address will not be published. Required fields are marked *