Parallel-spin degeneracy for equal-and-opposite moments
= Parallel-spin degeneracy for equal-and-opposite moments
If $g_2=-g_1$ in a shared magneton convention, the Zeeman <energy> of both parallel-spin states cancels. Their <energy> stays $\Delta/4$, with exact degeneracy two for every field. Opposite charges alone do not enforce this equality because the masses and magnetic factors may differ.