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
    BEYOND BORN-OPPENHEIMER: Molecular Dynamics Through a Conical Intersection (2004)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Physical Chemistry 55 (2004), S. 127-158 
    Details
    ISSN: 0066-426X
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Chemistry and Pharmacology , Physics
    Notes: Nonadiabatic effects play an important role in many areas of physics and chemistry. The coupling between electrons and nuclei may, for example, lead to the formation of a conical intersection between potential energy surfaces, which provides an efficient pathway for radiationless decay between electronic states. At such intersections the Born-Oppenheimer approximation breaks down, and unexpected dynamical processes result, which can be observed spectroscopically. We review the basic theory required to understand and describe conical, and related, intersections. A simple model is presented, which can be used to classify the different types of intersections known. An example is also given using wavepacket dynamics simulations to demonstrate the prototypical features of how a molecular system passes through a conical intersection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1146/annurev.physchem.55.091602.094335
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Electronic decay in weakly bound heteroclusters: Energy transfer versus electron transfer (2001)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 115 (2001), S. 5076-5088 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Inner-valence ionized states of weakly bound systems like van der Waals clusters can efficiently decay by electron emission. The mechanism of the decay, which does not occur in the isolated monomer units constituting the clusters has recently been shown to be of intermolecular/interatomic nature. This intermolecular/interatomic Coulombic decay (ICD) mechanism prevails in many systems ranging from hydrogen-bonded molecular clusters to atomic rare gas clusters. In the present paper we extend our previous studies to weakly bound heteroclusters built up of monomer units of largely differing energetics. It is shown that, as soon as the double ionization potential of a monomer unit is lower in energy than the ionization potential of the initially created inner-valence vacancy on a neighboring monomer unit, an additional electronic decay process can take place. In contrast to the ICD mechanism, which involves an efficient energy transfer between the monomer units, this second process is essentially based on an electron transfer process. It is therefore termed electron-transfer mediated decay (ETMD). We have analyzed the mechanisms of the electronic decay processes taking place following inner-valence ionization in weakly bound heteroclusters in an exemplary study of the NeAr dimer. The involved electronic states have been calculated using ab initio Green's function techniques. The lifetime of the inner-valence Ne(2s−1)Ar vacancy has been estimated and partitioned according to the contributions of the two decay channels based on a perturbation-theoretical description of the decay process. As a result, the lifetime of the inner-valence resonance state is estimated to be of the order of 10–100 fs, the specific value strongly depending on the internuclear separation of the monomers. The ICD process is shown to be by far the dominant decay channel at distances corresponding to bound states of the dimer. With decreasing internuclear separation the ratio of the ETMD and ICD decay widths quickly increases over several orders of magnitude. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1395555
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    An efficient combination of computational techniques for investigating electronic resonance states in molecules (2001)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 115 (2001), S. 6853-6861 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Calculating electronic resonance states in molecules is a serious challenge to theory, because the treatment of both the scattering and the many-electron problem is a formidable task. A very promising approach, known as CAP/CI, consists of the combination of a complex absorbing potential with the method of configuration interaction. In this paper we propose the combination of three distinct computational techniques in order to boost the performance of CAP/CI. A complex absorbing potential that can be adjusted flexibly to the geometry of the molecular scattering target is presented and its representation in a Gaussian basis set is discussed. To handle the large-scale complex symmetric eigenvalue problem arising in CAP/CI, a subspace projection method is employed and its validity is shown. We advocate the use of parallel filter diagonalization for calculating the eigenvectors required in the projection step. The proposed techniques are applied to determine the lifetime of an autoionizing, inner-valence excited state of Ne2+. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1405117
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The electronic structure of molecules by a many-body approach (1977)
    Springer
    Theoretical chemistry accounts 44 (1977), S. 85-93 
    Details
    ISSN: 1432-2234
    Keywords: C3H6 ring molecule, ionization potential of ∼ ; C2H4O ring molecule, ionization potential of ∼ ; C2H5N ring molecule, ionization potential of ∼
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The vertical valence ionization potentials of cyclopropane, ethylene oxide and ethylene imine are calculated by a many-body Green's function method. For C3H6 the ordering of the ionization potentials is 2e′(σ), 1e″(π), 2a′1(σ), 1a″2(π), 1e′(σ). The assignment of the 2a′1 and the 1a″2 ionization potentials which has been controversial is thus clarified. The ordering is in agreement with the result obtained via Koopmans' theorem. For ethylene oxide and ethylene imine Koopmans' theorem fails in predicting the correct order of ionic states. For C2H4O the ordering of the ionization potentials is 2b 1(π), 4a 1, 1a 2(π), 2b 2,3a 1, 1b 1(π), 1b 2, 2a 1 and for C2H5N 6a′, 5a′, 3a″, 2a″, 4a′, 3a′, 1a″, 2a′. The agreement of the computed ionization potentials with the experimental values is very satisfactory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00548031
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...