@article{FischerSchuetzBernhardtetal.2003, author = {Fischer, Markus and Sch{\"u}tz, Wolfgang and Bernhardt, Karl-Georg and Koch, Markus}, title = {Special feature : Plant population biology in al multidisciplinary context}, year = {2003}, language = {en} } @article{WolfParrishMyhreetal.2019, author = {Wolf, Thomas J. A. and Parrish, Robert M. and Myhre, Rolf H. and Martinez, Todd J. and Koch, Henrik and G{\"u}hr, Markus}, title = {Observation of Ultrafast Intersystem Crossing in Thymine by Extreme Ultraviolet Time-Resolved Photoelectron Spectroscopy}, series = {The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment \& general theory}, volume = {123}, journal = {The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment \& general theory}, number = {32}, publisher = {American Chemical Society}, address = {Washington}, issn = {1089-5639}, doi = {10.1021/acs.jpca.9b05573}, pages = {6897 -- 6903}, year = {2019}, abstract = {We studied the photoinduced ultrafast relaxation dynamics of the nucleobase thymine using gas-phase time-resolved photoelectron spectroscopy. By employing extreme ultraviolet pulses from high harmonic generation for photoionization, we substantially extend our spectral observation window with respect to previous studies. This enables us to follow relaxation of the excited state population all the way to low-lying electronic states including the ground state. In thymine, we observe relaxation from the optically bright (1)pi pi* state of thymine to a dark (1)n pi* state within 80 +/- 30 fs. The (1)n pi* state relaxes further within 3.5 +/- 0.3 ps to a low-lying electronic state. By comparison with quantum chemical simulations, we can unambiguously assign its spectroscopic signature to the (3)pi pi* state. Hence, our study draws a comprehensive picture of the relaxation mechanism of thymine including ultrafast intersystem crossing to the triplet manifold.}, language = {en} } @article{MyhreWolfChengetal.2018, author = {Myhre, Rolf H. and Wolf, Thomas J. A. and Cheng, Lan and Nandi, Saikat and Coriani, Sonia and G{\"u}hr, Markus and Koch, Henrik}, title = {A theoretical and experimental benchmark study of core-excited states in nitrogen}, series = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr}, volume = {148}, journal = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr}, number = {6}, publisher = {American Institute of Physics}, address = {Melville}, issn = {0021-9606}, doi = {10.1063/1.5011148}, pages = {7}, year = {2018}, abstract = {The high resolution near edge X-ray absorption fine structure spectrum of nitrogen displays the vibrational structure of the core-excited states. This makes nitrogen well suited for assessing the accuracy of different electronic structure methods for core excitations. We report high resolution experimental measurements performed at the SOLEIL synchrotron facility. These are compared with theoretical spectra calculated using coupled cluster theory and algebraic diagrammatic construction theory. The coupled cluster singles and doubles with perturbative triples model known as CC3 is shown to accurately reproduce the experimental excitation energies as well as the spacing of the vibrational transitions. The computational results are also shown to be systematically improved within the coupled cluster hierarchy, with the coupled cluster singles, doubles, triples, and quadruples method faithfully reproducing the experimental vibrational structure. Published by AIP Publishing.}, language = {en} } @misc{HerbstFranzkeWickeetal.2015, author = {Herbst, Uta and Franzke, Jochen and Wicke, Markus and Weber, Susann and Dobrigkeit, Philipp and Mikulcov{\´a}, Anna and Wanagas, Torsten and Sim, Chu-Won and Klosa, Sven and Geißler-Gr{\"u}nberg, Anke and Winter, Jean-Pierre and Koch, Helvi and Henrich, Lutz and K{\"o}nig, Julia and Stab, Uwe and Schmidt, Sina and Knuth, Alexander}, title = {Portal alumni}, series = {Das Ehemaligen-Magazin der Universit{\"a}t Potsdam}, journal = {Das Ehemaligen-Magazin der Universit{\"a}t Potsdam}, number = {12}, organization = {Stabsstelle Studierendenmarketing/Alumniprogramm Im Auftrag der Pr{\"a}sidentin der Universit{\"a}t Potsdam}, issn = {1613-2343}, doi = {10.25932/publishup-44529}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-445297}, pages = {68}, year = {2015}, abstract = {Die Beliebtheit von Medienberufen ist ungebrochen. Das zeigt sich unter anderem an der Zahl der Studieninteressierten. So haben sich allein in diesem Jahr mehr als 1 500 junge Leute auf einen der 44 Pl{\"a}tze f{\"u}r den Studiengang Medienwissenschaft an der Universit{\"a}t Potsdam beworben. Nach ihrem erfolgreichen Abschluss allerdings konkurrieren die Absolventen am Arbeitsmarkt mit Tausenden Abg{\"a}ngern anderer Hochschulen aus Film-, Medien- und Kommunikationsstudieng{\"a}ngen. Das sind allein in der Region Berlin-Brandenburg j{\"a}hrlich etwa 1 500. Doch nach jahrzehntelangem Boom der Medienbranche hat sich der Arbeitsmarkt im vergangenen Jahrzehnt drastisch ver{\"a}ndert. Konjunkturkrise, Kursr{\"u}ckg{\"a}nge und r{\"u}ckl{\"a}ufige Werbeinvestitionen schw{\"a}chten die Medien deutlich. Es folgten daraus schlechte Gewinnergebnisse, Einsparungen und Personalreduzierung, insbesondere bei den Printmedien. Die Insolvenz der Frankfurter Rundschau oder die Einstellung der Financial Times Deutschland sind nur zwei eklatante Beispiele. Auf der anderen Seite boomt der dynamische Online-Markt aufgrund des ver{\"a}nderten Nutzerverhaltens insbesondere der jungen Generation, die ihre Informationen zunehmend aus Internet, Apps und sozialen Netzwerken gewinnen. Die Berufsaussichten f{\"u}r all Jene, die „Irgendwas mit Medien" studieren wollen sind zwar aufgrund des Arbeitsmarktes schwieriger geworden, sie sind aber dennoch vielf{\"a}ltig. Guter Journalismus wird weiterhin ben{\"o}tigt und auch {\"O}ffentlichkeitsarbeiter sind gefragt. Dar{\"u}ber hinaus stehen Absolveninspiriert von den Fernsehbildern, als Tausende Fl{\"u}chtlinge herzlich in M{\"u}nchen empfangen wurden, kam unserem Kollegen Eric Makswitat die Idee, sich auch auf lokaler Ebene f{\"u}r die hier ankommenden Fl{\"u}chtlinge zu engagieren. Der Doktorand in der Politikwissenschaft sammelt {\"u}ber das Internet B{\"u}cher f{\"u}r Fl{\"u}chtlinge und gibt sie dann direkt in den Fl{\"u}chtlingsunterk{\"u}nften ab. Eric Makswitat ist einer von Vielen, die derzeit einen wichtigen Beitrag zur Bew{\"a}ltigung der Herausforderungen des Fl{\"u}chtlingszustroms nach Deutschland leisten. Die engagierten Helfer sind „ein Beweis daf{\"u}r, wie weit die Selbstorganisationskr{\"a}fte der organisierten B{\"u}rgerschaft in unserer Zivilgesellschaft mittlerweile entwickelt sind", meint dazu der Verwaltungswissenschaftler Jochen Franzke. Unser Kollege Eric ist auch in anderer Hinsicht beispielgebend. Er ist einer von rund achtzig Prozent aller ehemaligen Studierenden, die nach dem Studienabschluss in der Region bleiben, wie eine k{\"u}rzlich an der Uni ver{\"o}ffentlichte Studie zum Verbleib unserer Absolventinnen und Absolventen ermittelt hat. Unsere Alumni steigen ein in Berufsfeldern der Politik, Wirtschaft und Gesellschaft, sie gr{\"u}nden Firmen und sie engagieren sich beruflich, privat oder gesellschaftlich. Viele davon in Potsdam. Wenn die Universit{\"a}t Potsdam im n{\"a}chsten Jahr ihr 25-j{\"a}hriges Jubil{\"a}um in und mit der Stadt Potsdam feiern wird und mit Stolz auf hervorragende Leistungen aus Lehre und Forschung verweist, dann ist dies nicht zuletzt den Absolventinnen und Absolventen zu verdanken, die als hochqualifizierte Fachkr{\"a}fte neueste wissenschaftliche Erkenntnisse in die Praxis {\"u}berf{\"u}hren. Portal alumni ist deshalb in diesem Jahr hier, zu Hause in Potsdam geblieben. Wir haben Absolventen der Universit{\"a}t Potsdam gesucht, die heute in unterschiedlichen beruflichen und gesellschaftlichen Kontexten in der Region aktiv sind und sich engagieren.}, language = {de} } @article{WolfMyhreCryanetal.2017, author = {Wolf, T. J. A. and Myhre, R. H. and Cryan, J. P. and Coriani, S. and Squibb, R. J. and Battistoni, A. and Berrah, Nora and Bostedt, Christoph and Bucksbaum, Philip H. and Coslovich, G. and Feifel, R. and Gaffney, K. J. and Grilj, J. and Martinez, T. J. and Miyabe, S. and Moeller, S. P. and Mucke, M. and Natan, A. and Obaid, R. and Osipov, T. and Plekan, O. and Wang, S. and Koch, H. and Guehr, Markus}, title = {Probing ultrafast pi pi*/n pi* internal conversion in organic chromophores via K-edge resonant absorption}, series = {Nature Communications}, volume = {8}, journal = {Nature Communications}, publisher = {Nature Publ. Group}, address = {London}, issn = {2041-1723}, doi = {10.1038/s41467-017-00069-7}, pages = {14317 -- 14322}, year = {2017}, language = {en} } @article{LoebnerLomadzeKopyshevetal.2018, author = {Loebner, Sarah and Lomadze, Nino and Kopyshev, Alexey and Koch, Markus and Guskova, Olga and Saphiannikova, Marina and Santer, Svetlana}, title = {Light-Induced Deformation of Azobenzene-Containing Colloidal Spheres}, series = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, volume = {122}, journal = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, number = {6}, publisher = {American Chemical Society}, address = {Washington}, issn = {1520-6106}, doi = {10.1021/acs.jpcb.7b11644}, pages = {2001 -- 2009}, year = {2018}, abstract = {We report on light-induced deformation of colloidal spheres consisting of azobenzene-containing polymers. The colloids of the size between 60 nm and 2 mu m in diameter were drop casted on a glass surface and irradiated with linearly polarized light. It was found that colloidal particles can be deformed up to ca. 6 times of their initial diameter. The maximum degree of deformation depends on the irradiation wavelength and intensity, as well as on colloidal particles size. On the basis of recently proposed theory by Toshchevikov et al. [J. Phys. Chem. Lett. 2017, 8, 1094], we calculated the optomechanical stresses (ca. 100 MPa) needed for such giant deformations and compared them with the experimental results.}, language = {en} } @article{KochSaphiannikovaSanteretal.2017, author = {Koch, Markus and Saphiannikova, Marina and Santer, Svetlana and Guskova, Olga}, title = {Photoisomers of Azobenzene Star with a Flat Core: Theoretical Insights into Multiple States from DFT and MD Perspective}, series = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, volume = {121}, journal = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, publisher = {American Chemical Society}, address = {Washington}, issn = {1520-6106}, doi = {10.1021/acs.jpcb.7b07350}, pages = {8854 -- 8867}, year = {2017}, abstract = {This study focuses on comparing physical properties of photoisomers of an azobenzene star with benzene-1,3,5-tricarboxamide core. Three azobenzene arms of the molecule undergo a reversible trans-cis isomerization upon UV-vis light illumination giving rise to multiple states from the planar all-trans one, via two mixed states to the kinked all-cis isomer. Employing density functional theory, we characterize the structural and photophysical properties of each state indicating a role the planar core plays in the coupling between azobenzene chromophores. To characterize the light-triggered switching of solvophilicity/solvophobicity of the star, the difference in solvation free energy is calculated for the transfer of an azobenzene star from its gas phase to implicit or explicit solvents. For the latter case, classical all-atom molecular dynamics simulations of aqueous solutions of azobenzene star are performed employing the polymer consistent force field to shed light on the thermodynamics of explicit hydration as a function of the isomerization state and on the structuring of water around the star. From the analysis of two contributions to the free energy of hydration, the nonpolar van der Waals and the electrostatic terms, it is concluded that isomerization specificity largely determines the polarity of the molecule and the solute-solvent electrostatic interactions. This convertible hydrophilicity/hydrophobicity together with readjustable occupied volume and the surface area accessible to water, affects the self-assembly/disassembly of the azobenzene star with a flat core triggered by light.}, language = {en} }