Left panel: Angular velocity, ω, as a function of the ratio v_drift/v_th. The effective grain radii, a_eff = 0.1 μm to 1.4 μ m, are color-coded. Solid lines represent the average values of ω, while the shaded areas indicate the range between the minimum and maximum values. Dotted lines show the lower limit, 3 × ω_th, for long-term stable alignment, and dashed lines represent the upper limit for rotational disruption, ω_disr. Right panel: Same as the left panel, but for the Rayleigh reduction factor ℛ (solid lines). Dashed-dotted lines depict the parametric representation of ℛ for grains with a_eff ≥ 1 μm. See Sect. 2.2 for details.