Paramagnetic Resonance of I2− Centers in PH4I Single Crystals

Abstract

The I2 − centers have been produced by x irradiation of PH4 crystals at liquid‐nitrogen temperature and have been studied by electron paramagnetic resonance. The molecular axes of the centers were inclined 14.4° from the (001) plane, as might be expected from the crystal structure of PH4I. Constants of the spin Hamiltonian of I2 − in PH4I have been determined to be G‖ = 1.901 , g⊥ = 2.28 , A‖ = 364 G , A⊥ = 73 G , and | Q′ | = 68 G . From this data the admixture of 2 Π u wavefunction into the 2 Σ u + ground state of I 2 − is estimated to be about 15%.