Knight shift
The Knight shift is a shift in the nuclear magnetic resonance frequency of a paramagnetic substance first published in 1949 by the UC Berkeley physicist Walter D. Knight.
For an ensemble of N spins in a magnetic induction field ![\vec{B}](/Images/godic/202501/22/3441467fdbb94a7412b8b9cdc3a7aaf35703.png")
, the nuclear Hamiltonian for the Knight shift is expressed in Cartesian form by: