Hyperfine Structure of the Hydrogen Molecule in its MetastableΠu3State

The hfs of the hydrogen molecule in its metastable excited state ${}_{}{}^3{}_{}{}^{}\Pi _u^{}{}_{}{}^{}$ is calculated theoretically using Amemiya's wave function. The theoretical separation of the $F=3\mathrm{}$ and $F=2\mathrm{}$ states is 618 Mc/sec, and that for the $F=2\mathrm{}$ and $F=1\mathrm{}$ states is 412 Mc/sec, for $K=1\mathrm{}$, $J=2\mathrm{}$; these separations are to be compared with the observed values of 707.55 Mc/sec and 462.44 Mc/sec, respectively. The theoretical second-order correction is found to explain the deviation of the observed values from the interval rule.