Spectra calculated by this procedure are with respect to a relative chemical shift ∆. This relative chemical shift ∆ is equal to the chemical shift anisotropy (i.e. the line width of the NMR signal) of perfectly aligned, frozen CO2, which is known to be ∆= 𝛿 ⊥ -𝛿 || = 335 ppm. The linewidth of the calculated relative NMR signals can therefore directly be compared to the line width from experiment by multiplying it by ∆= 335 ppm.