text: # import the class model from the manual_fit module
  from optichem.manual_fit import model 
  s = model()
  
  # set the refractive index of the ATR crystal
  s.set_crystal_index(2.4 + 1j*1e-5)
  
  # set the refractive index of the ATR crystal (2.4 for diamond, 4 for Ge, 3.4 for Si, or 2.4 for ZnSe)
  s.set_angle_of_incidence(45)
  
  # set the refractivde index in the visible spectrum (usually found on materials SDS)
  s.set_n(1.367)
  
  # set x-axis input units of uploaded spectra and desried output units options include: '1/m', 'Hz', 'rad/s', 'nm', 'um', 'm', 'eV'
  s.set_input_units('1/cm')
  s.set_output_units('um')
  
  # upload ATR data file
  s.upload('ATR_measurements/IPA_ATR_data.txt')
  
  # set wavelength range manually
  s.set_range(6.75, 12.5) 
  
  # --- ADD MODES MANUALLY ---
  s.add_mode(6.82)
  s.add_mode(6.877)
  s.add_mode(7)
  s.add_mode(7.108)
  s.add_mode(7.264)
  s.add_mode(7.314)
  s.add_mode(7.462)
  s.add_mode(7.660)
  s.add_mode(8.617)
  s.add_mode(8.864)
  s.add_mode(9.04)
  s.add_mode(10.521)
  s.add_mode(12.236)
  
  
  # -- initiate 1st plot
  s._init_plot()
  
  # inital solver and plot results
  s.start_solver()
  s.plot_fit()
  
  # save optical property data
  s.save_optical_prop('optichem_results/IPA_optical_properties_manual.txt')
  
  # save vibrational modes for stiching
  s.save_modes('optichem_results/IPA_wL_range_2')