# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000        0.00164247        0.00511667    
     0.460000          0.700000        0.00488868        0.00290691    
     0.700000           1.00000        0.00546501        0.00353521    
      1.00000           1.54000              -NaN              -NaN    
      1.54000           2.40000              -NaN              -NaN    
      2.40000           4.80000              -NaN              -NaN    
      4.80000           10.0000        0.00700716         0.0100476