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offsets[ei][si][mi][oi] = frequency_to_rad_per_s(frq=cdp.spin_lock_offset[id], B0=frq, isotope=spin.isotope)
</source>
If you need to convert to ppm from Hz values, consider during this in your relax script. <br>
If for example you have recorded at a 800 MHz spectrometer, you could find the Carrier position for 15N (Value of yCar in NMRPipe scripts). If yCAR = 118.078 ppm, then
<source lang="python">
from lib.nmr import frequency_to_Hz, frequency_to_ppm
# Spectrometer frequency
sfrq = 799.7773991 # MHz
# Carrier position
yCAR = 118.078 # ppm
# We take the absolute value, since the gyromagnetic ratio of N15 is negative.
yCAR_Hz = abs(frequency_to_Hz(frq=yCAR, B0=sfrq*1E6, isotope='15N'))
# We add the offset (deltadof2 in varian pulse sequences) in Hz, and from 0 to 10.000
yCar_offset_Hz = yCAR_Hz + float(deltadof2)
# The convert back from Hz to ppm. Again absolute value, because of the gyromagnetic ratio of N15 is negative.
yCar_offset_ppm = abs(frequency_to_ppm(frq=yCar_offset_Hz, B0=sfrq*1E6, isotope='15N'))
relax_disp.spin_lock_offset(spectrum_id=sp_id, offset=yCar_offset_ppm)
</source>
'''Offset in the literature'''<br>