Hydrogen atom in a spherical box. II. Effect on hyperfine energy of excited state admixture

The exact eigenfunctions of the hydrogen atom H0 trapped in a finite sphere are used to evaluate radial averages and allow, for example, evaluation of 〈r−3〉 to yield the 2p hyperfine interaction energy. Inclusion of compressed 2p orbital in the ground state permits simultaneous fitting of the relatively large hyperfine anisotropy and the isotropic component, observed by EPR for H0 in α-quartz, with an acceptable sphere radius and an admixture coefficient a2p more reasonable (smaller) than is possible with the ordinary hydrogenic 2p orbital. The local uniform electric field required to generate the desired a2p value is estimated.