</source>
Then $\bar{\Omega_SOmega}_S$ is calculated with: $\bar{\Omega}_{S,i} = \bar{\omega}_{S,i} - \omega_{rf}$, where $\bar{\omega}$ is the population averaged Larmor frequency of the spin and comes from the conversion of the [[wikipedia:Chemical_shift | Chemical Shifts]] $\delta_{S,i}$ to frequency $\bar{\omega}_{S,i}$.
<source lang="python">
Delta_omega = shifts[ei][si][mi] - offsets[ei][si][mi][oi]