Fig. 1: The CFM model results.

The fitting results of the CFM model for differnet sampling points: a three sampling points (Step 1); b 19 sampling points (Step 17); c 27 sampling points (Step 25); d CFM XAS curve convergence, with the colored dots denote in order the results of Fig. 1a to c. The upper panels in (a)-(c) show the fitted results of fBO, where the black curve denotes the standard real values of the unknown XAS curves, the black dots are the already measured points, the red curve is the fitted result based on current sampled points using the fBO fitting, and the magenta cross is the point to be measured in the next round, which is determined by sBO. In the lower panels are the standardized prediction of sBO, where the black dots denote the GP predicted loss with the blue-shaded regions denoting the uncertainties. The parameter comparison for the listed steps is shown in Supplementary Table 4.