Library

You have 0 saved results.
Mark results and click the "Add To Watchlist" link in order to add them to this list.
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
    s.l. : American Chemical Society
    Analytical chemistry 65 (1993), S. 128-134 
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Analytical chemistry 65 (1993), S. 153-157 
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Analytical chemistry 65 (1993), S. 2663-2670 
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 5207-5221 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We report the large scale calculation of accurate vibrational eigenstates of X˜ state HCN/HNC up to ∼37 000 cm−1. The discrete variable representation-distributed Gaussian basis (DVR-DGB) approach is used. In the final major computational step, large dense Hamiltonian matrices (≥11 000 rows or columns) must be diagonalized. The use of new software for out-of-core eigenproblems is described in some detail. Representative wave functions of high lying vibrational eigenstates near the isomerization barrier and at energies up to 39 313 cm−1 are presented. Theoretical stimulated emission pumping (SEP) spectra for several initial (A˜) vibrational states are presented along with calculations of the quantum survival probability for these spectra. The spectra range from being dominated by localized eigenstates to being dominated by delocalized eigenstates, depending on the geometry of each initial state. In addition, time-dependent expectation values of the coordinates of the evolving wave packet are plotted.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 6722-6734 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We have established in this study the capabilities of the wave operator (WO) algorithm to extract from a huge primitive space a smaller subspace (the active space) containing all of the zero order states which play an active role during the intramolecular vibrational energy redistribution (IVR) from an initial state ||i(approximately-greater-than)0. While exact methods such as the recursive residue generation method (RRGM) or the Chebychev algorithms can only be applied in a primitive space containing less than about 200 000 states, the WO algorithm can be used efficiently in ultralarge basis sets containing billions of states. The recursive residue generation method (RRGM) or Chebychev methods can then be applied in this active space which typically contains less than 10 000 states. In order to draw general conclusions on the efficiency of such a method and on the main features of IVR phenomena, we have concurrently studied IVR from the fifth CH overtone in the nine mode CD3H molecule and from the second CH overtone in the 16 mode C6H6 system. We have analyzed the main features of the active space and have shown that the WO algorithm selects the important states. A very broad energy distribution of states in the active space has been obtained for these two systems. We have also shown that C6H6 is a very complex system to study; while only a few hundred states are effectively populated during the IVR from the fifth CH overtone in CD3H, about 8000 states have to be considered in order to accurately study IVR from the second CH overtone in C6H6. However, we have shown that the WO method is able to reproduce correctly both the survival probability of the initial state and the intricate energy flow through the molecule during the first picosecond. Finally, we have shown that the WO algorithm builds a far more efficient active space than a more traditional artificial intelligence (Al) tree pruning procedure.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 6758-6768 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Large-scale quantum mechanical calculations of the CH(v=3) overtone spectrum and survival probability are reported for 21-mode planar benzene. A valence coordinate hybrid force field built from the following two sets of ab initio information was used: (1) the quartic DZP/SCF force field recently reported by Maslen et al.; (2) a force field computed at the 6-311G/MP2 level for the overtone excited CH chromophore. Comparisons are made between these results and the overtone spectrum and survival probability computed using the older Pulay et al. 4-21P/SCF scaled quadratic plus cubic force field. In addition, comparisons are made with experimental spectra from two research groups. These comparisons provide information about the sensitivity of the computed results to alterations in the input force field.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 2261-2264 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Large scale quantum calculations on relaxation from the CH(v=3) overtone in benzene are reported. Plots of time-dependent local mode stretch and bend energies were used to elucidate the relaxation mechanism. Sequential local mode excitation was observed at early times (t〈0.2 ps). Persistent oscillations were found superimposed upon the steady state bond energies at later times.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 5191-5206 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: This series is concerned with the quantum dynamics of overtone relaxation in benzene and in reduced mode benzene fragments. In part III of this series, emphasis is placed on the CH(v=3) overtone spectrum and the survival probability for both 16 mode (five CH stretch modes are forced to remain inactive out of 21 planar modes) and 21 mode planar benzene models. Through use of the wave operator contraction algorithm, primitive vibrational basis sets containing up to 9×109 states are contracted to active spaces containing 2000–7000 states. The exact dynamics within the active space is developed with the recursive residue generation method (RRGM). Specific results reported in this study include the following: (a) a comparison is made between dipole spectra and residue spectra, the former explicitly involving the CH dipole function; (b) for the 16 mode model, the following quantities are displayed: overtone spectrum, survival probability of the initial state, complex-valued autocorrelation function, number of phase space cells explored as a function of time, and the rate of exploring phase space cells; (c) sensitivity of the overtone spectrum to the size and composition of the active space built with the wave operator contraction algorithm; (d) for 21 mode benzene, we consider the sensitivity of the overtone spectrum to "softening'' the anharmonic potential; (e) comparisons are made with recent jet cooled beam experimental overtone spectra.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 3577-3578 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The first large scale quantum mechanical calculations of the benzene CH(v=4) overtone spectrum are reported. These results are compared with recent experimental studies.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 64 (1993), S. 2320-2325 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: X-ray diodes driven by repetitively pulsed Blumleins have been shown to be able to deliver high dose rates of x rays in pulses of nanosecond duration. Reported here is a study of the scaling of such devices conducted to isolate the primary factors limiting performance. Low residual gas pressure in the output diode together with the critical alignment of the electrodes were found essential for enhanced output. Optimizations served to increase the x-ray yield by an order of magnitude and the resulting performance is reported. At the output window, dose rates exceeding 1.4 kR min−1 were obtained in nanosecond pulses from the finished device of table top size at a charging voltage of 30 kV and a pulse repetition rate of 50 Hz.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...