title: Electronic structure of the nucleobases.
abstract: We present a comparison between experimental and calculated soft X-ray spectra of DNA's nucleobases, adenine (A), guanine (G), cytosine (C), and thymine (T) using X-ray absorption spectroscopy (XAS) and soft X-ray emission spectroscopy (XES). Spectra of the 1s thresholds of carbon, nitrogen, and oxygen give a complete picture of the occupied and unoccupied partial density of states of the nucleobases. A combination of both Hartree-Fock and density functional theory calculations are used in the comparison to experimental results. Most experimental results agree well with our theoretical calculations for the XAS and XES of all bases. All spectral features are assigned. A comparison of the experimental highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps is made to the diverse values predicted in the literature.
authors.affiliation: Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada. janay.m@usask.ca
authors.forename: J
authors.initials: J
authors.lastname: MacNaughton
authors.forename: A
authors.initials: A
authors.lastname: Moewes
authors.forename: E Z
authors.initials: EZ
authors.lastname: Kurmaev
mesh_terms: D000225:Adenine / Q000737:chemistry*; D003596:Cytosine / Q000737:chemistry*; D006147:Guanine / Q000737:chemistry*; D013057:Spectrum Analysis; D013941:Thymine / Q000737:chemistry*; D014965:X-Rays
chemical_list: D006147:Guanine; D003596:Cytosine; D000225:Adenine; D013941:Thymine