The defect, D(a), (cf. Eq. (15)) as a function of grain radius a for different values of the turbulence speeds v_turb and with initial dust velocities = v₀ = 0 and with infall rate of gas Ṁ = 0.002 M_⊙ Myr⁻¹ shown in thin lines. Red line: Coulomb forces, excluding photo-electric effect, taken into account with an ionization ratio of n(e)/n(H)=2.72 × 10⁻⁴. Thick line: doubled infall rate, v_turb = 1 km s⁻¹. Dashed line: initial speed v₀= initial free-fall velocity of the gas, v_turb = 1 km s⁻¹, Ṁ = 0.002 M_⊙ Myr⁻¹.