1.2.7.12 nanodroplet vapor diffusion method, using 0.01 M nickel chloride, 20% (w/v) PEG MME 2000 and 0.1 M Tris pH 8.5 710739 1.2.7.12 nanodroplet vapor diffusion method, using 0.2 M magnesium nitrate and 20% (w/v) PEG 3350 or 10% (w/v) PEG 8000, 0.2 M zinc acetate and 0.1 M MES pH 6.0 710739 1.2.7.12 nanodroplet vapor diffusion method, using 0.2 M MgCl2 and 20% (w/v) PEG 3350 710739