Vertical spreading of icy grains at r = 100 au for different mixing strengths α_mix. Results are shown as a function of the vertical hydrogen nuclei column density N_〈H〉. The top row of plots shows the computed gas and dust temperatures, T_g and T_d. The middle row of plots shows the bare grain surface area per H nucleus = 4π〈a²〉n_d/n_〈H〉 after dust settling in blue, and the number of ice layers on each grain N_layers in red. The lower plots show the concentrations of selected ice species.