The observed quantum diffusion of orthohydrogen impurities in solid parahydrogen is interpreted as due to resonant ortho-para conversion. The contribution due to intermolecular interchange is shown to be completely negligible because of "motional narrowing" due to the quadrupolar interaction between the ortho impurities.
No takes yet. Share an insight, caveat, or question.
Oyarzún et al. (1971) studied this question.