Fig. 9

Difference \(\int _{\infty }^{\infty } |S^{LBE}-S^{Mac}| df_{s}\) in the spectrum of spontaneous (a) and coherent (b) RBS between solutions of LBE and macroscopic equations. Note that before the comparison, areas of RBS spectra are normalized to unity. The solution may be viewed to be accurate when the relative difference is less than 0.05. Note that super-Burnett with θ₇=−15/4, Brenner’s, and Dadzie’s equations are purely phenomenological models with arbitrary tuned parameters to give their best results, while other macroscopic equations in this figure are derived without any parameter tuning