Pseudoquadrupole interaction

The g = h term has been considered by P. Pyykkoo and J. Linderbarg in On Nuclear Pseudoquadrupole Interactions in Lithium Fluoride and Lithium Bromide Molecules, Chem. Phys. Lett. 5, 34 (1970) and is shown to yield a very small effect. 

A hyperfine effect has been described which can generate a temperature-dependent shift of the centroid of the resonance lines only in rare circumstances. This is the pseudoquadrupole hyperfine interaction [64]. 

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