Regensburg 2007 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 14: Biological Systems
CPP 14.1: Talk
Tuesday, March 27, 2007, 10:00–10:15, H47
DFT studies for structure, energetics, dynamics and electronics of glycine, alanine, and cysteine — •Robert Maul1, Karsten Hannewald2, Frank Ortmann2, Martin Preuss2, and Friedhelm Bechstedt2 — 1Institut fuer Nanotechnologie, Forschungszentrum Karlsruhe, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen — 2Institut fuer Festkoerpertheorie und -optik, Friedrich-Schiller-Universitaet, Max-Wien-Platz 1,07743 Jena, Germany
The gas-phase geometries of the most stable conformers of glycine, alanine, and cysteine were optimized using a plane-wave density functional theory implementation in the VASP code. Different approximations for the exchange-correlation functional like LDA, GGA-PW91, and the hybrid functional PBE0 allow for an estimation of the non-local contribution of the functional to several geometry parameters and relative energies. Furthermore we calculated dipole moments and infrared spectra of the three most stable conformers of glycine, alanine and cysteine in good agreement with experimental results. In addition the calculated ionisation- and two particle excitation energies deviate only by 3% from the experimental values. Therefore it can be concluded that DFT-GGA performs comparably well with respect to accuracy and the speed of calculation, which permits the investigation of more complicated systems.