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MM: Fachverband Metall- und Materialphysik
MM 43: Computational Materials Modelling - Transport, Excitations, Time Dependence II
MM 43.4: Vortrag
Mittwoch, 13. März 2013, 17:15–17:30, H24
photo-emission spectroscopy study for the tautomeric populations of DNA and RNA nucleobases: an application of koopmans' compliant functionals. — •ngoc linh nguyen1, giovanni borghi1, Nicola Marzari1, Andrea Ferretti2, and Ismaila Dabo3 — 1Theory and Simulation of Materials (THEOS), Ecole Polytechnique Federale de Lausanne — 2CNRNANO, Universie di Modena e Reggio Emilia — 3CERMICS, Universite Paris-Est
We study the structural and photo-electron properties of five DNA and RNA nucleobases - guanine (G),adenine (A), cytosine (C), thymine (T), and uracil (U), using either Perdew-Zunger self-interaction corrections [1] to density-functional theory, or Koopmans' compliant functionals [2]. A simple method for simulating photoemission spectra of molecules is also implemented, based on a plane-wave approximation for the final states to account for the transmission matrix. Finally, the experimental photoemission spectra are modelled by summing the individual spectra of each tautomer, weighed by the Boltzmann population ratios for the tautomers. Our calculations show that Koopmans' compliant functionals provide vertical ionization energies compatible with the values computed by high-accuracy quantum chemistry methods, and spectra that are in remarkable agreement with experimental results.
[1] J. P. Perdew and Alex Zunger, Phys. Rev. B 23, 5048 (1981).
[2] I. Dabo1, A. Ferretti, N. Poilvert, Y. Li, N. Marzari, and M. Cococcioni, Phys. Rev. B 82, 115121 (2010).