Figures ) ~ (f) illustrate the regression results of eq. 4 with different accuracy and hosts. Specifically, A: the regression with the highest Adj. R 2 , B: the regression with the highest Adj. R 2 in the base-like host, C: the regression with medium Adj. R 2 , and D: the regression with the lowest Adj. R 2 , indicated by arrows in Figure (a), respectively. Even in the regression results with the lowest Adj. R 2 , the mean absolute error (MAE) is not considerably large. It appears that the small Adj. R 2 is due to the narrower energy range of the Eint distribution. This indicates that the performance of regression using eq. 4 can capture the overall trend of stability even in the worst case.