# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000              -NaN              -NaN    
     0.460000          0.700000         0.0559965         0.0317306    
     0.700000           1.00000              -NaN              -NaN    
      1.00000           1.54000              -NaN              -NaN    
      1.54000           2.40000         0.0344652        0.00641120    
      2.40000           4.80000         0.0355302        0.00485502    
      4.80000           10.0000         0.0296071        0.00588512