Hi Edward. Just to confirm math symbols. http://www.nmr-relax.com/manual/Dispersion_model_summary.html I would like to add these to x_axis of dispersion graphs. For Spin-lock field strength in Hz, I will use greek_letter "nu_1". Spin-lock field strength in rad/s is greek_letter "omega_1". But what is the math symbol to use for cpmg frq CPMG pulse train in Hz? Best Troels