Determination of the Singlet-Triplet Separation ofH2by a "Level-Anticrossing" Technique

Abstract

We show that the singlet-triplet separation of ${\mathrm{H}}_2$ must be lowered by 157.7 ± 0.2 ${\mathrm{cm}}^{-1\mathrm{}}$ compared to the hitherto accepted value of Dieke. We have used a new kind of "level anticrossing" method in which the anticrossing is due to the coupling of a singlet and a triplet state by spin-orbit or hyperfine Fermi contact interaction.