Two-power-law parameterization shown as a red line for CA (left) and SC (right) BA grains in comparison with the full set of the numerical DDSCAT simulations (black dots) for grains of size a_eff = 200 nm, where the absolute value of the torque efficiency |Q_Γ| is plotted as a function of λ/a_eff. The constant part c is fitted for each grain size up to a value of λ/a_eff = 3, the steeper power-law is fit as a linear function to the logarithm of the data for all sizes combined in the interval 3 < λ/a_eff < 10, and the same for the shallow power law in the interval λ/a_eff > 20. Finally, the two intersection points a and b were calculated and used to create a continuous parameterization for |Q_Γ| (see Eq. (13)).