# energy_low(keV)  energy_high(keV)  fractional_rms  fractional_rms_error
     0.300000          0.460000         0.0146549         0.0146323    
     0.460000          0.700000         0.0223671         0.0111169    
     0.700000           1.00000         0.0149281         0.0182306    
      1.00000           1.54000              -NaN              -NaN    
      1.54000           2.40000        0.00772627         0.0175412    
      2.40000           4.80000        0.00792793         0.0140228    
      4.80000           10.0000              -NaN              -NaN