Discussion of the Absolute Shielding Values in Table

The two other methods suggested by Deverell - the T and the 6 vs. T2 methods in the abbreviated terminology of Table 6.1 - have some attractive features. There are indications of a correlation between quadrupolar coupling constants and shielding values for halide nuclei in covalent halogen compounds (cf. Subsection 3.1.3) - corre- 

Op is the paramagnetic contribution to the shielding for an aqueous ion X. The crucial step in the application of the 6 vs. T method lies in the allowance for the variations of the correlation time t 

Furthermore, as discussed in Subsection 5.1.3, direct proportionality between ionic relaxation rates and solution viscosity is not observed experimentally. Two other weak points in Deverell s treatments are  

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