Angular momentum luminescence

The free energy of the annihilation reaction can be evaluated from the one-electron potentials for oxidation and reduction of the species involved and the zero-zero emission energy, Eqq, of the luminescent product. The excited state formed can be either singlet or triplet spin multiplicity (or both). If strict spin conservation is observed in the process, the products will contain 75 % triplet and 25 % singlet however, hyperfine interactions provide alternate avenues for angular momentum conservation [13, 14]. 

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