Nuclear magnetic shielding absolute

A. Benchmark Calculations and Absolute Nuclear Magnetic Shielding Constants... 

Even though the contributions to the absolute value of the nuclear magnetic shielding of the heavy nucleus are very large, they are almost insensitive to the change in chemical environment from HX to CH3X. 

In this section we will illustrate the calculation of electromagnetic properties taking the electric dipole moment jl Eq. (4.40) in Table 13.1, the static electric dipole polarizability a Eq. (4.52) in Table 13.2, the absolute nuclear magnetic shielding constant a Eq. (5.67) in Table 13.3 and the indirect nuclear spin-spin coupling constants J... 

Puzzarini, C., Cazzoli, G., Harding, M. E., Vazquez, J., and Gauss, J. (2009). A new experimental absolute nuclear magnetic shielding scale for oxygen based on the rotational hyperfine structure of H2 0. J. Chem. Phys., 131, 234304. 

Vaara, J., Pyykko> P. (2003). Relativistic, nearly basis-set-limit nuclear magnetic shielding constants of the rare gases He-Rn A way to absolute nuclear magnetic resonance shielding scales. Journal of Chemical Physics, 118, 2973. 

NUCLEAR MAGNETIC SHIELDING AND THE CHEMICAL SHIFT I.l. The Absolute Shielding Tensor... 

Another way in which chemical shifts can be related to absolute shielding is by the comparison of the nuclear magnetic moment (measured by the NMR method for an atom in a molecule) with the moment for the free atom. This has been done with considerable accuracy for hydrogen (SO) and also for lead (50). 

Nuclear-independent chemical shift (NICS) is the negative value of absolute magnetic shielding calculated at revealing points in or near an aromatic system. Rings with negative NICS and NICS(l) values computed at the center... 

The nuclear shielding constant (a) is an absolute measure of the electronic distribution about the nucleus and its effect on the observed magnetic moment of that nuclei in the applied magnetic field, which is sensitive to a molecule s chemical structure and local solvation environment. The nuclear shielding for a molecule can be related to (23)... 

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