Configuration mixing and K -forbidden E 2 decays

Hindrance factors for $K$-forbidden $E2$ decays from multiquasiparticle isomers are analyzed in relation to mixing matrix elements that are often associated with chance near degeneracies, and a functional relationship is established. Focusing on effective matrix elements for $\mathrm{\ensuremath{\Delta}}K=6$ decays from three-quasiparticle isomers, significant configuration dependence is demonstrated.