Dresden 2003 – wissenschaftliches Programm

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SYSE: Simulation and experiment

SYSE 2: Poster (gemeinsam mit SYCN und CPP)

SYSE 2.2: Poster

Dienstag, 25. März 2003, 19:00–21:00, ZEU/250

Ground- and excited-state properties of DNA base molecules from first-principles calculations — •Martin Preuß, Wolf G. Schmidt, and Friedhelm Bechstedt — Institut für Festkörpertheorie und Theoretische Optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany

Detailed knowledge of the geometrical and electronic structure of the DNA base molecules is of crucial importance for the understanding of the static and dynamic properties of nucleic acids and polynucleotides. From a theoretical point of view, reliable data from gas-phase studies on isolated molecules are needed to allow for the modeling of polynucleotide chains. Moreover, the scrutiny of biologically relevant molecules in the gas-phase can, in comparison to experiments, help to elucidate, e. g., the role of charge transfer through DNA strands and radiation-induced damage. We present equilibrium geometries, dipole moments, ionisation energies, electron affinities, vibrational properties and optical absorption spectra of the DNA base molecules adenine, thymine, guanine, and cytosine calculated from first principles. The comparison of our results with experimental data and results obtained by using quantum chemistry methods indicate that gradient-corrected density functional theory (DFT) calculations using ultrasoft pseudopotentials and a plane-wave basis is a numerically efficient and accurate alternative to methods employing localized orbitals for the expansion of the electron wave functions.