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
Filter
  • 1990-1994  (3)
  • 1
    Electronic Resource
    Electronic Resource
    The dipole moment of carbon monoxide (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 6660-6663 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The dipole moment of CO has been calculated with many-body perturbation theory (MBPT) and coupled cluster (CC) methods using basis sets which have been optimized at the MBPT-2 level. It is demonstrated that triple excitations as well as g-type functions in the basis set are crucial to obtain satisfactory agreement with experiment. The most reliable prediction (0.125 D) is obtained at the CCSD(T) (coupled cluster including all single, double, and connected triple excitations, perturbatively) level of theory using a 10s9p4d2f1g basis set (160 basis functions). This result is in excellent agreement with the experimental value of 0.122 D.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.460293
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Nuclear magnetic shieldings and spin rotation constants of HF and N2 (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 92 (1990), S. 6036-6042 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The paramagnetic contribution to the nuclear magnetic shieldings and the spin rotation constants are calculated using polarization propagator theory. Results are reported both in the first order approximation [equivalent to the coupled Hartree–Fock (CHF) method] and in the second order polarization propagator approximation (SOPPA). It is demonstrated how the constant Cgauge which gives the gauge origin dependence of the total nuclear magnetic shielding in a finite basis set [σ(Rc+d)=σ(Rc)+d⋅Cgauge] can be calculated from the polarization propagator. The magnetic shieldings of H and F in HF are nearly the same in CHF and SOPPA and results from both levels of theory agree well with experiment. For N2, σ(SOPPA)=−72.2 ppm, also in good agreement with the most recent measurement. However, for N2 there is a large correlation effect since σ(CHF)=−106.5 ppm. The computed spin rotation constant for N2 is M(15N)=20 kHz, i.e., about 2 kHz lower than its measured value. This value of M(15N) corresponds to σ(N)=−72.2 ppm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.458375
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Angular dependence of geminal spin-spin coupling constants in a prototype CH2 group. J(H,H) versus interbond angle in methane (1993)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 31 (1993), S. 722-725 
    Details
    ISSN: 0749-1581
    Keywords: Spin-spin coupling ; angle variations ; methane ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Correlated ab initio calculations of the dependences of the proton-proton spin-spin coupling constant J(H1, H2) in methane with the variation of the H1—C—H2 interbond angle are reported. The other coupling constants, including J(C, H), were simultaneously calculated. The coupling constants J(H1, H2) and J(C, H1) increase nearly linearly with the opening of the interbond angle whereas J(H2, H3) and J(C, H3) decrease. J(H3, H4) is only very slightly affected. The changes are due almost solely to changes in the Fermi contact term. The angular dependence is slightly larger at the SCF level of calculation than at the correlated level. The change in the geminal coupling constant J(H1, H2) with respect to equilibrium geometry is given to within 0.025 Hz by ΔJ(H1, H2) (Hz) = 41.57 sin α12 - 8.90 sin2 α12, where α12 is the increase in the interbond angle with respect to equilibrium ( - 10° ≤ α12 ≤ 10°).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260310806
    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...