title: A TDDFT study of the optical response of DNA bases, base pairs, and their tautomers in the gas phase.
abstract: We present calculations of the optical response of the DNA bases and base pairs both in their normal and tautomeric forms in the gas phase, using time-dependent density functional theory (TDDFT). These calculations are performed in real time within the adiabatic approximation with a basis of local orbitals. Our results for the individual bases are in good agreement with experiment and computationally more demanding calculations of chemical accuracy. The optical response of base pairs indicates that the differences between normal and tautomeric forms in certain cases are significant enough to provide a means of identification.
authors.affiliation: Department of Physics and Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Argyrios
authors.initials: A
authors.lastname: Tsolakidis
authors.forename: Efthimios
authors.initials: E
authors.lastname: Kaxiras
mesh_terms: D000225:Adenine / Q000737:chemistry* / Q000528:radiation effects; D001482:Base Composition; D020029:Base Pairing; D003596:Cytosine / Q000737:chemistry* / Q000528:radiation effects; D004247:DNA / Q000737:chemistry*; D005740:Gases; D006147:Guanine / Q000737:chemistry* / Q000528:radiation effects; D008027:Light; D008958:Models, Molecular; D015394:Molecular Structure; D044367:Phase Transition; D011789:Quantum Theory; D013057:Spectrum Analysis; D013237:Stereoisomerism; D013941:Thymine / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D005740:Gases; D006147:Guanine; D003596:Cytosine; D004247:DNA; D000225:Adenine; D013941:Thymine