Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Rotational energy distribution of products in fast hydrogen atom–molecule collisions (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 5486-5492 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Starting from the formalism of collisional time-correlation functions, an expression is derived for the double differential cross section (with respect to scattering angles and final rotational energies) of molecules with a thermal distribution of initial rotational states, colliding with fast atoms. This expression is valid when the duration of the collision is short compared with the periods of internal motions of target molecules. The formulation leads to simple distributions in terms of error functions, which can be used to parametrize experimental results. The parameters in turn give the average rotational energy and its standard deviation for the final state. This procedure is followed to interpret recent experimental measurements of the final rotational distributions of CO and CO2 colliding with fast hydrogen atoms obtained from the photolysis of hydrides. For CO(v=1) and CO2(0001), in which the collisions are impulsive, the derived formula fits the experimental distribution very well. For CO(v=0), in which long-duration, complex-forming collisions play an important role, an additional statistical distribution can be introduced to satisfactorily explain the experimental results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.456453
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The eikonal approximation to molecular photodissociation: Application to CH3I (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 5501-5509 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The selfconsistent eikonal treatment is applied to the photodossociation of CH3 I by near ultraviolet light. A model based on two potential-energy surfaces is used as in previous studies, to compare our results with other treatments. State-to-state transition probabilities are calculated from eikonal wave functions constructed from classical trajectories and their divergence, using a recently developed procedure which avoids the generation of trajectory bundles. Numerical results have been obtained for cross sections versus light wavelength and for each vibrational state of the methyl fragment. Our results are in very good agreement with wave packet calculations. In addition, we have calculated these cross sections for several initial vibrational states of CH3 I, for some of which the total cross sections show several maxima.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.456455
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Nonlinear optical response and yield in the femtosecond photodesorption of CO from the Cu(001) surface: A density matrix treatment (2002)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 116 (2002), S. 5173-5185 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The dynamics of molecular photodesorption from a metal surface is described by a density matrix theory of the nonlinear optical response resulting from the interaction of a femtosecond pulsed laser with a metal surface. The extended system is divided into a primary region comprising the adsorbate species and the bonding substrate atoms and a secondary region consisting of the remaining substrate, that interact strongly and self-consistently with each other through an electric dipole-electric dipole coupling. The formalism uses the Liouville–von Neumann equation, with an effective Hamiltonian which includes the effects of energy dissipation into the metal. The nonlinear response of the substrate is studied by solving the optical Bloch equations with relaxation terms to account for the effects of energy dissipation, coupled to kinetics equations describing the excitation of the electron Fermi sea by the light pulse. A primary effective hamiltonian with a nonlinear dependence on the electric field strength of the laser is obtained as a result. The theory is applied to the CO/Cu(001) adsorbate–substrate complex and the nonlinear photodesorption yield of CO versus pulse fluence is evaluated through model calculations. The local electric field at the adsorbate, and the yields for several fluence values are obtained as functions of the desorption time. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1448486
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Die Rolle der Molekülimpulsverteilung bei starken Stößen (1978)
    Springer
    Colloid & polymer science 256 (1978), S. 705-705 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01784434
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Generating wave functions from classical trajectory calculations: The divergence of streamlines (1987)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 32 (1987), S. 239-244 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Wave functions can be written, for short de Broglie wavelengths, in an eikonal form where the preexponential factor relates to the divergence of streamlines. A method is presented to calculate this divergence by generating the Jacobian of a variable transformation along a classical trajectory without requiring the simultaneous integration of adjacent trajectories. For a system with N + 1 degrees of freedom, there are 2(N + 1)2 differential equations that must be solved simultaneously to generate the trajectories and the Jacobian. Results are presented for a photodissociation cross section calculation in which the eikonal wave functions have been used in the transition integrals.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560320726
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Time evolution of CO vibrational populations during photodesorption by light pulses (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 64 (1997), S. 71-83 
    Details
    ISSN: 0020-7608
    Keywords: Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We describe the direct photodesorption of CO from the Ni(001) metal surface during the absorption of a short pulse of UV light by the adsorbate and account for the dynamics of the desorbing species coupled to electronic excitations of the substrate, which lead to energy dissipation. The interaction potentials and couplings for the ground and excited states are obtained from electronic structure calculations and from experimental information. The time evolution of CO vibrational populations is studied for propagating wavepackets for the adsorbate-substrate complex with a split-operator algorithm, followed by a perturbative treatment of dissipation and response to the light pulse. Direct photodesorption is found to occur predominantly in the excited electronic state and is compatible with dissipation. Results are presented for CO photodesorption by Gaussian pulses with several durations to show the effect of light pulse shapes on the time evolution of populations. Shorter pulses in the femtosecond range are shown to give relatively larger populations of excited vibrational states during the desorption of CO.   © 1997 John Wiley & Sons, Inc. Int J Quant Chem 64: 71-83, 1997
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...