TY - JOUR A1 - Mitrić, Roland A1 - Hartmann, Michael A1 - Stanca, B. A1 - Bonačić-Koutecký, Vlasta A1 - Fantucci, P. T1 - Ab Initio Adiabatic Dynamics Combined with Wigner Distribution Approach to Femtosecond Pump−Probe Negative Ion to Neutral to Positive Ion (NeNePo) Spectroscopy of Ag2Au, Ag4, and Au4 Clusters JF - Journal of Physical Chemistry A N2 - Ultrafast ground state nuclear dynamics of small coinage metal clusters is theoretically explored in the framework of negative ion to neutral to positive ion (NeNePo) femtosecond pump−probe spectroscopy with the aim to determine the scope and perspective of this technique. This approach involves the preparation of an initial ensemble in the anionic ground state of the cluster, one-photon detachment by the pump pulse, the propagation of the system on the neutral electronic ground state, and detection via the cationic ground state by a time-delayed ionizing probe pulse. The calculations of the NeNePo-ZEKE signals under the condition of zero kinetic energy electrons are based on the combination of the Wigner distribution approach and ab initio molecular dynamics (MD) “on the fly” in the framework of gradient-corrected DFT for the propagation of an ensemble of classical trajectories and involves the average over the entire phase space. We have chosen examples of Ag2Au and Au4 to investigate time scales and the character of isomerization processes that are influenced by a local minimum corresponding to an energetically high-lying isomer with the structure related to the initial anionic structure. Capture of the nuclei within the local minimum takes place with dephased (Ag2Au) or nondephased (Au4) vibrational relaxation. Structural relaxations leading to isomerization processes are in both cases of delocalized nature and take place after 1 ps. In contrast, the Ag4 cluster represents an example for which isomerization processes do not occur, since rhombic structures with slightly different bond lengths are global minima of the anionic and neutral ground states. Therefore, the relaxation dynamics is characterized by regular oscillations, which serve as fingerprints of structural properties. On the basis of the analysis of pump−probe signals and underlying dynamics, this contribution provides information about conditions under which structural properties of gas-phase clusters (global and local minima) and isomerization processes can be observed in the framework of the NeNePo-ZEKE type of spectroscopy. The latter is important in the context of applicability of this technique to the investigation of cluster reactivity. KW - Physical chemistry Y1 - 2001 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Fulltext due to copyright not available. VL - 105 IS - 39 SP - 8892 EP - 8905 ER - TY - JOUR A1 - Bonačić-Koutecký, Vlasta A1 - Hartmann, Michael A1 - Pittner, Jiřı́ T1 - Theoretical exploration of ultrafast spectroscopy of small clusters JF - The European Physical Journal D N2 - We present the ultrafast multistate nuclear dynamics involving adiabatic and nonadiabatic excited states of non-stoichiometric halide deficient clusters (NanF) characterized by strong ionic bonding and one-excess electron for which the "frozen ionic bonds" approximation has been justified allowing to consider the optical response of the single excess electron in the effective field of the other electrons. We combined the Wigner-Moyal representation of the vibronic density matrix with the ab initio multi state molecular dynamics in the ground and excited electronic states including the nonadiabatic couplings calculated "on the fly" at low computational demand. This method allows the simulation of femtosecond pump-probe and pump-dump signals based on an analytical formulation, which utilizes temperature dependent ground state initial conditions, an ensemble of trajectories carried out on the electronic excited state as well as on the ground state after the passage through the conical intersection in the case of nonadiabatic dynamics and for probing either in the cationic state or in the ground state. The choice of the systems we presented has been made in order to determine the timescales of the fast geometric relaxation leaving the bonding frame intact as during the dynamics in the first excited state of Na4F3, and of the bond breaking processes leading to conical intersection between the first excited state and the ground state as in Na3F2. The former is the smallest finite system prototype for an surface F-center of bulk color centers. The latter allows to study the photo isomerization in full complexity taking into account all degrees of freedom. In the case of Na4F3 after the fast geometric relaxation in the excited state leading to deformed cuboidal structure without breaking of bonds, different types of internal vibrational redistribution (IVR) processes have been identified in pump-dump signals by tuning the dump laser. In contrast, from the analysis of the pump-probe signals of Na3F2 cluster, the timescales for the metallic and the ionic bond breaking, as well as for the passage through conical intersection have been determined. Finally the conditions under which these processes can be experimentally observed have been identified. KW - Optical Physics KW - Molecular Physics Y1 - 2001 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0298-opus4-5536 VL - 16 SP - 133 EP - 138 ER - TY - JOUR A1 - Hartmann, Michael A1 - Mitrić, Roland A1 - Stanca, B. A1 - Bonačić-Koutecký, Vlasta T1 - Theoretical investigation of the ultrafast NeNePo spectroscopy of Au4 and Ag4 Clusters JF - The European Physical Journal D N2 - Ultrafast ground state nuclear dynamics of Au4 and Ag4 is theoretically explored in the framework of negative ion - to neutral - to positive ion (NeNePo) pump-probe spectroscopy based on the ab initio Wigner distribution approach. This involves the preparation of a nonequilibrium neutral ensemble by pump induced photodetachment of a thermal anionic ground state distribution, gradient corrected DFT classical trajectory simulations "on the fly" on the neutral ground state, and detection of the relaxation process of the ensemble in the cationic ground state by a time-delayed probe pulse. In Au4, the initially prepared linear structure is close to a local minimum of the neutral state giving rise to characteristic vibrations in the signals for probe wavelength near the initial Franck-Condon transition. A timescale of ~1 ps for the structural relaxation towards the stable rhombic D neutral isomer was determined by the increase of the signal for probe wavelength in vicinity of the vertical ionization energy of the rhombic structure. In contrast, the relaxation dynamics in Ag4 is characterized by normal mode vibrations since both the initially prepared anionic ground state and the neutral ground state have rhombic minimum geometries. Thus, time-resolved oscillations of pump-probe signals are fingerprints of structural behaviour which can be used experimentally for the identification of particular isomers in the framework of NeNePo spectroscopy. KW - Molecular physics KW - Optical physics Y1 - 2001 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0298-opus4-5542 VL - 16 SP - 151 EP - 155 ER - TY - JOUR A1 - Hartmann, Michael A1 - Pittner, Jiřı́ A1 - Bonačić-Koutecký, Vlasta T1 - Ab initio nonadiabatic dynamics involving conical intersection combined with Wigner distribution approach to ultrafast spectroscopy illustrated on Na3F2 cluster JF - The Journal of Chemical Physics N2 - We present a theoretical study of a femtosecond photo isomerization process due to a nonadiabatic radiationless decay from the first excited state through a conical intersection occurring in one of the nonstoichiometric halide-deficient clusters with one excess electron (Na3F2). This is an extension of the adiabatic dynamics study presented in the accompanying paper [J. Chem. Phys. 114, 2106 (2001)] for other members of the NanFn−1 series characterized by a strong ionic bonding for which the “frozen ionic bonds” approximation has been justified, allowing consideration of the optical response of the single excess electron in the effective field of the other electrons. In this contribution we outline the extension of the ab initio Wigner-distribution approach to nonadiabatic molecular dynamics which combines the Wigner–Moyal representation of the vibronic density matrix with the ab initio multistate molecular dynamics in the ground- and excited electronic states including the nonadiabatic coupling computed “on the fly” in connection with the fewest-switches hopping algorithm. This scheme allows accounting for temperature-dependent initial conditions, for the propagation in the excited state and in the ground state after the passage through the conical intersection, and for probing in the cationic ground state as well as for deriving analytic expressions for the pump–probe signals which utilize an ensemble of classical trajectories obtained at low computational demand. Our approach permits investigation of the photo isomerization through the conical intersection due to the long amplitude motion in the Na3F2 system in full complexity, taking into account all degrees of freedom. After breaking of one metallic and of one ionic bond the conical intersection occurs at the linear geometry and involves states of different symmetry which differ in the translocation of the one excess electron or positive charge localized at the Na atom from one end to the other of the system and separates two isomers with Cs and C2v structures. From the analysis of the nonadiabaticdynamics, the time scales for the metallic bond breaking of ∼90 fs and for the ionic bond breaking of ∼220 fs, for the passage through the conical intersection after ∼0.4 ps and for the internal vibrational energy redistribution (IVR) of more than 0.9 ps for the individual isomers, have been determined. The simulated fs pump–probe signals confirm the above results and provide the information about the experimental conditions such as laser frequencies and pulse duration under which bond breaking of different type as well as the population of each of the two isomers after the passage through the conical intersection can be identified. In this contribution we show that the mechanism of the photo isomerization at a conical intersection due to a long amplitude motion can occur in atomic clusters and is not necessarily limited to organic photochemistry. KW - Wigner distribution KW - Chemical physics Y1 - 2001 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Fulltext due to copyright not available. VL - 114 IS - 5 SP - 2123 EP - 2136 ER - TY - JOUR A1 - Hartmann, Michael A1 - Pittner, Jiřı́ A1 - Bonačić-Koutecký, Vlasta T1 - Ab initio adiabatic dynamics involving excited states combined with Wigner distribution approach to ultrafast spectroscopy illustrated on alkali halide clusters JF - The Journal of Chemical Physics N2 - We investigate the ultrafast multistate nuclear dynamics involving adiabatic electronic excited states of nonstoichiometric halide deficient clusters (NanFn−1) characterized by strong ionic bonding and one excess electron, which is localized either in the halide vacancy or on the alkali atom attached to the ionic subunit depending on the cluster size. For this purpose we developed an ab initio adiabatic nuclear dynamics approach in electronic excited and ground states “on the fly” at low computational demand by introducing the “frozen ionic bonds” approximation, which yields an accurate description of excited states considering the excitation of the one excess electron in the effective field of the other n−1 valence electrons involved in the ionic bonding. We combined this multistate dynamics approach with the Wigner–Moyal representation of the vibronic density matrix forming the ab initio Wigner distribution approach to adiabatic dynamics. This method allows the simulation of femtosecondNeExPo-pump–probe and NeExNe-pump–dump signals based on an analytic formulation which utilizes temperature-dependent ground-state initial conditions (Ne), an ensemble of trajectories carried out on the electronic excited state (Ex) for the investigation of the dynamics of the system, and either the cationic (Po) or the ground state (Ne) for the probing step. The choice of the systems has been made in order to determine the time scales of processes involving (i) metallic bond breaking such as during the dynamics in the first excited state of Na2F, and (ii) fast geometric relaxation leaving the bonding frame intact as during the dynamics in the first excited state of Na4F3. The bond-breaking process via a conical intersection involving nonadiabatic dynamics will be presented in the accompanying paper [Hartmann et al., J. Chem. Phys. 114, 2123 (2001)]. The dynamics in the first excited state of Na2F from triangular-to linear-to triangular structure gives rise to fast geometric relaxation due to Na–Na bond breaking at the time scale of ∼90 fs but no signature of internal vibrational energy redistribution (IVR) is present in NeExNe-pump–dump signals since the broken metallic bond prevents the coupling between stretching and bending modes. Instead, anharmonicities of the bending periodic motion have been identified. In contrast, in the case of Na4F3, which is the smallest finite system for a surface F-center prototype of bulk color centers, after the geometric relaxation in the excited state of ∼100 fs leading to the deformed cuboidal type of structure without breaking of bonds, different types of IVR have been identified in NeExNe signals by tuning the dump laser: one-mode selective energy leaving IVR, resonant, and restricted energy arriving IVR corresponding to the selection of different parts of the phase space. Dissipative IVR could not be identified in NeExNe signals of Na4F3 at low initial temperature on the time scale up to 2 ps in spite of 15 degrees of freedom. Due to similar structural and electronic properties such as F centers in bulk, these findings can serve as guidance for establishing the time scales for geometric relaxation and IVR in excited states of larger systems. KW - Wigner distribution KW - Chemical physics Y1 - 2001 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Fulltext due to copyright not available. VL - 114 IS - 5 SP - 2106 EP - 2122 ER - TY - CHAP A1 - Gocek, Pawel A1 - Hartmann, Michael A1 - Schleusener, Heinz A1 - Timčák, Geza T1 - Webportal using Web 2.0 Technology for the Špis Region T2 - 5th International Conference on Perspectives of rural tourism in the New Europe, Košice N2 - Portals are called web sites which are designed to offer services and/or an outline of special subjects. They have been developed as fast as information data bases and electronic communication facilities were extended. Recently, portals with geographically referenced information became important and popular for different fields like geo information systems of cities (see e. or the presentation of economically relevant data in the context of regional marketing, foreign direct investment or tourism by indicating important objects like public institutions, companies, hotels, sights, etc. on maps. In this manner they may contribute to the improvement of industrial structure and the marketing of a region. For representing geographical data on maps, applications with special client-server-architecture have to be developed. There are different solutions for the Internet using HTML and JavaScript, Flash or Java Applets. In our contribution we discuss currently available solutions and show an alternative approach. Our solution is based on the Java Applet technology and Asynchronous JavaScript and XML (Ajax). This technology is part of the web solutions known as Web 2.0 which is strongly discussed and developed in the present. Our results are demonstrated as a user-friendly web application with data of the Slovakian region Špis (Zips). An extended version of this web solution could be nicely incorporated into a modern concept for tourism of the Špis region. KW - Web 2.0 KW - Tourism Y1 - 2006 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Full text not available for copyright reasons. SP - 48 EP - 54 ER - TY - CHAP A1 - Kohler, L. A1 - Hartmann, Michael A1 - Schleusener, Heinz A1 - Timčák, Geza T1 - Web 2-presentation of regional data T2 - 5th International Conference on Perspectives of rural tourism in the New Europe, Košice N2 - Web portals and many Internet solutions contain objects with a geographical reference such as the position of a company or a tourist attraction. Existing maps are protected by copyright. The licence fee is high and it is very expensive and complicated to create own maps. Freely useable and suitable maps for presentations, such as open source, do not exist – although the project OpenGeoDB is growing day after day. Recently, however some changes occurred. After a registration, Yahoo and Google offer interfaces to their map data for non-commercial users. This can be used for free. The interfaces offer advanced user possibilities for accessing maps, which are mostly high resolution ones, using the Web 2 methods. We show how to integrate Google´s API interface into one's own web applications and finally, how regional data, stored in a database, can be presented by this solution. Currently, Google does not have sufficiently detailed maps for Eastern Europe yet. Nevertheless, our web solution uses data of the region Zips (Špis) in Slovakia. It demonstrates how geo-based data can be used for supporting regional marketing concepts by Web 2 in the future. KW - Regional data Y1 - 2006 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Fulltext due to copyright not available. SP - 55 EP - 58 ER - TY - CHAP A1 - Hartmann, Michael A1 - Lieberum, Uta A1 - Plewka, Tomas A1 - Sauer, Petra A1 - Schweikart, Joachim A1 - Yossa Nou b ikou, Jean-Jacques A1 - Schleusener, Heinz T1 - Development of Geo-Based interactive Web Portals for Joint Ventures-Problems and Challenges T2 - Informatika a felsőoktatásban, Debrecen N2 - Keine Angabe No details KW - Geo-based KW - Web portals Y1 - 2005 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Fulltext due to copyright not available. ER - TY - CHAP A1 - DeMore, Jaime A1 - Brauner, Elisabeth A1 - Gockel, Christine T1 - Can team productivity be improved by counteracting detrimental effects of cognitive loafing on transactive memory? T2 - 75th Annual Convention of the Canadian Psychological Association, Vancouver N2 - Keine Angabe - No details KW - Psychology KW - Team productivity KW - Transactive memory Y1 - 2014 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Fulltext due to copyright not available. ER - TY - CHAP A1 - Gockel, Christine A1 - Werth, Lioba T1 - Are funny groups more creative?: humor, cohesion, and creativity in small groups T2 - 4th Annual INGRoup Conference, Colorado Springs N2 - Keine Angabe - No details KW - Psychology KW - Humor KW - Creativity KW - Cohesion Y1 - 2009 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Fulltext due to copyright not available. ER - TY - CHAP A1 - Gockel, Christine T1 - Effects of put-down humor on cohesion in groups T2 - 2nd Annual INGRoup Conference, East Lansing N2 - Keine Angabe No details KW - Psychology KW - Cohesion KW - Put-Down Humor Y1 - 2007 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Fulltext due to copyright not available. ER - TY - CHAP A1 - Gockel, Christine A1 - Wittenbaum, Gwen M. T1 - Influence in dyadic decision-making: arguing for what one believes or does not believe T2 - 2nd Annual INGRoup Conference, East Lansing N2 - Keine Angabe No details KW - Psychology KW - Decision-making Y1 - 2007 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Fulltext due to copyright not available. ER - TY - CHAP A1 - Gockel, Christine A1 - Wittenbaum, Gwen M. A1 - Hollingshead, A. B. A1 - Raile, A. T1 - Disentangling two explanations for biased information exchange in mixed-motive decision-making groups T2 - 1st Annual INGRoup Conference, Pittsburgh N2 - Keine Angabe No details KW - Psychology KW - Biased information exchange Y1 - 2006 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Fulltext due to copyright not available. ER - TY - CHAP A1 - Gockel, Christine A1 - Kerr, Norbert L. A1 - Qureshi, A. A1 - Park, Ernest S. T1 - Message uniformity as a moderator of majority/minority influence T2 - 78th Annual Meeting of the Midwestern Psychological Association, Chicago N2 - Keine Angabe No details KW - Psychology Y1 - 2006 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Fulltext due to copyright not available. ER - TY - JOUR A1 - Gocek, Pawel A1 - Hartmann, Michael A1 - Schleusener, Heinz T1 - Modern Technologies in Client-Server Architecture for Geo-based Interactive Web Portals JF - Journal of Universal Computer Science N2 - The internet is an unlimited growing and most comfortable information and communication base. In this context, web portals on the internet play an important role created for combining communication facilities and information data bases. An increasing number of portals involve web-based map applications to integrate geographic information for the representation of economical and other records. Web-based map applications are typically designed in a client-server architecture. Different solutions exist using especially HTML and JavaScript, Flash or Java applets. We discuss these possibilities and point out an alternative solution. Particularly, we show how to use Java Applet Technology and Asynchronous JavaScript and XML (Ajax) in this field. Finally, we report about our results as a complete, flexible map service solution which is available on the internet. An adapted kind of solution will be used by a geo-based marketing portal for offering information about the economic situation, social and cultural aspects and natural facts of regions to support joint-ventures inside the European Union. KW - Web-based services KW - Map services KW - XML KW - Geo-base KW - Java Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0298-opus4-5335 VL - 12 IS - 9 SP - 1208 EP - 1214 ER - TY - CHAP A1 - Gocek, Pawel A1 - Hartmann, Michael A1 - Schleusener, Heinz T1 - Modern Technologies in client-server Architecture for Geo-Based Webportals: represented by examples for Companies in Food Technology and Food Industry T2 - Proceedings of the 7th International Conference on Food Science, Szeged N2 - In the last decade, portals on the WWW have been extensively developed for different applications in e-business, e-commerce, e-government or science and are used as an information and communication base. Recently, due to the progression of web- technologies, new user-friendly features could be added into portals. Among them the incorporation of geographic informations became most important since many relevant data are related to space. In such a way the value and the appropriate visualization of the relevant information as well as the ability to investigate the interrelation between different data could be reached (Bernhardt, 02). Geo-based web portals combine the features of common portals like searching for keywords or navigating with geo information systems (GIS). For a certain target group they provide a unique presentation of all relevant information within a region or a market, and provide user specific communication tools. In this context, providing maps is one of the main characteristics of geo-based web portals. Creating a geo-referenced map is a challenging and complex task since all relevant geo data like streets, objects, information of the landscape etc. have to be known and incorporated into the GIS. Therefore, a geo-object in the geo-based web portal has to contain both the geo-data and the content related data. Geo-data describe the structure of an object in space whereas the content related data provide additional attributes associated with the properties of the object (Dickmann & Zehner 2001). From the point of the architecture, a web-based map application consists of two essential components - the server and the client part. Typically, the server component is responsible for providing geographical information according to the client's request and returns the data and images suitable for the visualization back to the client application. The client component provides the user with a graphical user interface (GUI). Its main tasks are collecting the user input data and communicating with the server in order to retrieve the information as well as to provide interactive mechanisms for representing analyzing the results. The communication between the client and the sever component via a HTTP port is based on a defined request-response protocol. Typical solutions are implemented using JavaScript, Java applets or Flash and are discussed in more detail in the next section. In this contribution we describe an alternative approach using the Java Applet Technology, Asynchronous JavaScript and XML (Ajax). It's application for offering informations of companies operating in the field of food technology and food industry is shown. In such a way it represents a realization of our recently developed concept of a geo-based web portal (Hartmann et al, 05). KW - Geo-base KW - Web-based services KW - Food technology KW - Food industry Y1 - 2006 ER - TY - CHAP A1 - Gockel, Christine A1 - Wittenbaum, G. M. T1 - Information sharing in competitive decision-making groups: biased cognition or strategic communication? T2 - 7th Annual Meeting of the Society for Personality and Social Psychology, Palm Springs N2 - Keine Angabe No details KW - Information sharing KW - Communication Y1 - 2006 N1 - Volltext aus urheberrechtlichen Gründen nicht verfügbar. Fulltext due to copyright not available. ER -