Simulated Solid State Spectrum - Comparison with Experiment

Simulated Solid State Spectrum - Comparison with Experiment 

The methyl unit is comparably well met the experimental features - main contribution around 19 ppm and large upheld shoulder - are clearly visible in the simulated spectrum, too. The methine resonance is quite narrow both in the experiment and the simulation moreover, a small but extended down-field shoulder is reproduced. It should be recalled, however, that the position of one y-neighbor of the methine carbons investigated (Bi, B2 in Fig. 15.c) was not specified in the course of the simulation. Thus, the theoretical results are only indicative of a trend. 

The good overall agreement of experiment and theory refers to shape and width and not to absolute chemical shift values. In fact, the absolute values of the chemical shift are not properly reproduced due to the small atomic basis employed vide infra. Sect. 4.3). Thus, the position of the simulated spectrum was adjusted for each resonance separately. 

The shape of the bands in the spectrum is given by differences of the shift of the same nucleus within the same molecule, but different geometries, viz. 

In this expression, errors in the absolute value (which are due to the small atomic basis) cancel almost completely. Consequently, for our purposes, the 

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