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
    From Intermolecular Potentials to the Spectra of van der Waals Molecules, and Vice Versa (1994)
    s.l. : American Chemical Society
    Chemical reviews 94 (1994), S. 1931-1974 
    Details
    ISSN: 1520-6890
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/cr00031a009
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Frequency-dependent polarizabilities and van der Waals coefficients of half-open-shell systems in the time-dependent coupled Hartree–Fock approximation (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 3389-3396 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: In this paper we present a derivation of time-dependent coupled Hartree–Fock (TDCHF) theory for the case of half-open shells. With this method frequency-dependent polarizabilities are calculated for the hydrogen and nitrogen atom, as well as for the diatomics CN, NH, and OH+. van der Waals coefficients of the half-open-shell systems with the H atom and the H2 molecule are computed. Other dispersion coefficients for dimers consisting of these monomers are available upon request.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.458818
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The nonempirical calculation of second-order molecular properties by means of effective states. III. Correlated dynamic polarizabilities and dispersion coefficients for He, Ne, H2, N2, and O2 (1985)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 82 (1985), S. 3753-3764 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Intramolecular correlation contributions to long-range dispersion interactions between closed shell and open shell molecules have been studied by means of perturbation calculations in bases of configuration state functions. All necessary dynamic polarizabilities have been calculated in large bases for He, Ne, H2, N2, and O2. These calculations employ a modified version of an algorithm which was published recently. Basis sets consisting of single and double substitutions from the reference function have been employed. It is shown that in a basis of unperturbed SCF-MO's the truncation of the configuration basis at the single and double CI level does not give a satisfactory description of the correlation effects. The inclusion of triply excited states is studied for the Ne atom. This improves the results considerably. The possible extension of the present approach to larger systems is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.448912
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Intramonomer correlation contributions to first-order exchange nonadditivity in trimers (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 3159-3169 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: An expression for the nonadditive first-order exchange contribution in terms of the one- and two-particle density matrices of the isolated monomers is given. This formula is used to derive the intramonomer correlation contribution to the first-order exchange nonadditivity with the density matrices of the isolated monomers computed at the second-order Møller–Plesset level. As an illustrative example of the theory the trimer Ar2–HF is considered. It is shown that the correlation contribution is far from negligible, not only in relation to the corresponding first-order uncorrelated exchange, but also in comparison to the other three-body terms. Moreover, it is fairly anisotropic, so that it cannot be neglected in accurate calculations of nonadditive effects. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.480901
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Intermolecular potential and rovibrational levels of Ar–HF from symmetry-adapted perturbation theory (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 6076-6092 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A two-dimensional intermolecular potential energy surface for Ar–HF has been calculated using the many-body symmetry-adapted perturbation theory (SAPT). The H–F distance was kept constant at its equilibrium value. The interaction energies have been computed using an spdfg-symmetry basis optimized for intermolecular interactions. In addition, the dispersion and induction energies have been calculated in a few progressively larger basis sets to determine the basis set convergence and validity of the asymptotic scaling of those components. Converged results for the dispersion energy have been obtained by using a large basis set containing spdfgh-symmetry orbitals. The ab initio SAPT potential agrees well with the empirical H6(4,3,2) potential of Hutson [J. Chem. Phys. 96, 6752 (1992)], including a reasonably similar account of the anisotropy. It predicts an absolute minimum of −207.4 cm−1 for the linear Ar–HF geometry at an intermolecular separation of 6.53 bohr and a secondary minimum of −111.0 cm−1 for the linear Ar–FH geometry at an intermolecular separation of 6.36 bohr. The corresponding values for the H6(4,3,2) potential are −211.1 cm−1 at an intermolecular separation of 6.50 bohr and −108.8 cm−1 at an intermolecular separation of 6.38 bohr. Despite this agreement in the overall potentials, the individual components describing different physical effects are quite different in the SAPT and H6(4,3,2) potentials. The SAPT potential has been used to generate rovibrational levels of the complex which were compared to the levels predicted by H6(4,3,2) at the equilibrium separation. The agreement is excellent for stretch-type states (to within 1 cm−1), while states corresponding to bending vibrations agree to a few cm−1. The latter discrepancies are consistent with the differences in anisotropies of the two potentials. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.470436
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Ab initio potential energy surface, infrared spectrum, and second virial coefficient of the He–CO complex (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 321-332 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Symmetry-adapted perturbation theory has been applied to compute the intermolecular potential energy surface of the He–CO complex. The interaction energy is found to be dominated by the first-order exchange contribution and the dispersion energy. The ab initio potential has a single minimum of εm=−24.895 cm−1 for the linear CO–He geometry at Rm=6.85 bohr. The computed potential energy surface has been analytically fitted and used in converged variational calculations to generate bound rovibrational states of the He–CO molecule and the infrared spectrum, which corresponds to the simultaneous excitation of vibration and internal rotation in the CO subunit within the complex. The predicted positions and intensities of lines in the infrared spectrum are in good agreement with the experimental spectrum [C.E. Chuaqui et al., J. Chem. Phys. 101, 39 (1994)]. The theoretical potential was also checked by comparison of computed excess second virial coefficients with the experimental data. The ab initio interaction virial coefficients, including quantum corrections, lie within the experimental error bars over a wide range of temperatures. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.469644
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Ab initio potential energy surface and near-infrared spectrum of the He–C2H2 complex (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 102 (1995), S. 8385-8397 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Symmetry-adapted perturbation theory has been applied to compute the intermolecular potential energy surface of the He–C2H2 complex. The interaction energy is found to be dominated by the first-order exchange contribution and the dispersion energy. In both contributions it was necessary to include high-level intramolecular correlation effects. Our potential has a global minimum of εm=−22.292 cm−1 near the linear He–HCCH geometry at Rm=8.20 bohr and cursive-thetam=14.16°, and a local minimum at a skew geometry (Rm=7.39 bohr, cursive-thetam=48.82°, and εm=−21.983 cm−1). The computed potential energy surface has been analytically fitted and used in converged variational calculations to generate bound rovibrational states of the He–C2H2 molecule and the near-infrared spectrum, which corresponds to the simultaneous excitation of the vibration and hindered rotation of the C2H2 monomer within the complex. The nature of the bound states and of the spectrum predicted from the ab initio potential are discussed. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.468830
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Symmetry-adapted perturbation theory of nonadditive three-body interactions in van der Waals molecules. I. General theory (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 8058-8074 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Symmetry-adapted perturbation theory of pairwise nonadditive interactions in trimers is formulated, and pure three-body polarization and exchange components are explicitly separated out. It is shown that the three-body polarization contributions through the third order of perturbation theory naturally separate into terms describing the pure induction, mixed induction–dispersion, and pure dispersion interactions. Working equations for these components in terms of molecular integrals and linear and quadratic response functions are derived. These formulas have a clear, partly classical, partly quantum mechanical, physical interpretation. The asymptotic expressions for the second- and third-order three-body polarization contributions through the multipole moments and (hyper)polarizabilities of the isolated monomers are reported. Finally, assuming the random phase approximation for the response functions, explicit orbital formulas for the three-body polarization terms are derived. The exchange terms are also classified, and the simplest approximations (neglecting intramonomer correlation effects) are written as explicitly connected commutator expressions involving second-quantized operators. The corresponding orbital formulas are also reported. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.470171
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Near-infrared spectrum and rotational predissociation dynamics of the He–HF complex from an ab initio symmetry-adapted perturbation theory potential (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 2825-2835 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Starting from an ab initio symmetry-adapted perturbation theory potential energy surface we have performed converged variational and close-coupling calculations of the bound rovibrational states and of the positions and widths of rotationally predissociating resonances of HeHF and HeDF van der Waals complexes. The energy levels were used to compute transition frequencies in the near-infrared spectra of these complexes corresponding to the simultaneous excitation of vibration and internal rotation in the HF(DF) subunit in the complex. The computed transition energies and other model independent characteristics of the near-infrared spectra are in excellent agreement with the results of high-resolution measurements of Lovejoy and Nesbitt [C. M. Lovejoy and D. J. Nesbitt, J. Chem. Phys. 93, 5387 (1990)]. In particular, the ab initio potential predicts dissociation energies of 7.38 and 7.50 cm−1 for HeHF and HeDF, respectively, in very good agreement with the Lovejoy and Nesbitt results of 7.35 and 7.52 cm−1. The agreement of the observed and calculated linewidths is less satisfactory. We have found, however, that the linewidths are very sensitive to the accuracy of the short-range contribution to the V1(r,R) term in the anisotropic expansion of the potential. By simple scaling of the latter component we have obtained linewidths in very good agreement with the experimental results. We have also found that this scaling introduces a very small (2%) change in the total potential around the van der Waals minimum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.467597
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Damage to Polythene by Aquatic Moths (1965)
    [s.l.] : Nature Publishing Group
    Nature 207 (1965), S. 104-104 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Recently the larvae of an aquatic lepidopteran species were found damaging the polythene linings of ponds (1,000 gauge, approx. 0-25 mm thick). The damage to the inner lining of the pond was caused by the larvae of the moth eating holes through the polythene to the rough paper outer-lining. The ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/207104a0
    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...