Supplementary Fig. 3: Extrapolated electron density maps (1.5 σ contour level).

a, 3 ps at LCLS (Pande et al.¹⁴). b - c, 10 ps, 30 ps and 80 ps at EuXFEL. e, 100 ps at APS (Jung et al. ³³). The extrapolated maps were calculated from 13,722, 13,142, 13,014, 12,889 and 13,214 extrapolated structure factors for the 3 ps to 100 ps time delays, respectively.