Theoretical Calculation of the Ortho—Para Hydrogen Transition Rate on a Paramagnetic Solid Surface

Abstract

The theoretically expected conversion rate of the ortho—para hydrogen molecular transition on a solid surface was calculated on the basis of the difference of proton-spin flip rates caused by a paramagnetic ion in the surface. It is concluded that the electron-spin relaxation time of the paramagnetic ion greatly affects the conversion rate, with the ions having long relaxation times being better catalysts. The calculated conversion rates were found to be much greater than those experimentally observable and the causes for the discrepancy are discussed.