Basis Set Effects on NMR Calculations Benzene

Determine the effect of basis set on the predicted chemical shifts for benzene. Compute the NMR properties for both compounds at the B3LYP/6-31G(d) geometries we computed previously. Use the HF method for your NMR calculations, with whatever form(s) of the 6-31G basis set you deem appropriate. Compare your results to those of the HF/6-311+G(2d,p) job we ran in the earlier exercise. How does the basis set effect the accuracy of the computed chemical shift for benzene  

Exploring Chemistry with Electronic Structure Methods 

Model Absolute Shielding Value TMS Benzene Relative Shift 

Recall that the observed chemical shift is 130.9. For the B3LYP geometry, all of the computations using the 6-31G(d) basis set—however augmented—are substantially less accurate than the one using the 6-311+G(2d,p) basis set.  

This exercise examines the effect of basis set on the computed equilibrium structure of N,N -Dimethylformamide. 

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