2) gradually increases from the initial 0.14 nm at 0 s, to ~0.20 nm after 60 s, which is a ~40% increase (Fig. ). If we approximate ξ OZ in terms of an equivalent radius of a sphere, R, the parameters follow the relationship: R =5/3⋅ ξ OZ ≃ 2.89ξ OZ (Supplementary Material: 3