Fig. 2: Data obtained from this work plotted alongside shock compression literature data and Hugoniot data.

Three methods to obtain the peak pressure for each run, detailed in the Supplementary Materials, are represented for the LV13 campaign. Pressure values calculated from the measured density values obtained from the X-ray diffraction images are plotted as green points. Pressure values determined from the calibration equation described by Equation (3) are plotted as red points. Pressure values for runs 097 and 099 were found by VISAR impedance matching and are plotted as purple points (note that VISAR data for the other runs is not available due to the high opacity of the LiF window at high pressures). For the L10075 campaign, pressure from the measured density values is represented as open green points, whereas pressure from VISAR measurements is shown as open purple points. Circles represent runs where fcc-Ni was observed, whereas squares represent runs where fcc-Ni and liquid were observed. Data from the shock compression literature is shown as black crosses^{36,37,38,41,42,43,44,65}. An exponential fit to the literature data is represented as a black line, with 95% confidence intervals shown as gray dashed lines. This exponential fit included data up to 1000 GPa, which is not pictured above. Three Hugoniot models are also shown. In orange is the Ni SESAME 83103 multi-phase Hugoniot, in blue is the Ni SESAME 3100 single-plase Hugoniot, and in pink is the Ni Hugoniot by Prisbrey^92,93,94.