An introduction to Solid State NMR and its Interactions

The NMR signal in theory
st=Tr 〚 I exp −i H t I x exp i H t 〛
Initial state:
I x
System evolves under:
H
One quantum transitions are observed:
I
st∝∑ m
∣〈m1∣I ∣m 〉∣ 2 ×exp −i m, m1 t
The NMR frequencies
m, m1 =〈m1∣ H∣m1〉−〈m∣ H∣m〉
The contribution of each transition
to the signal amplitude is (isotropic !!)
∣〈m1∣I ∣m 〉∣ 2
Hamiltonian of NMR interactions are needed H
DFT calculations provide H !