**19.3. EPR spectra**

Ni2+(d8) has no unpaired electron (square planer) in its orbit. Therefore it does not exhibit EPR signal at room temperature.

But in certain conditions, it shows EPR signal. The EPR data could be related with the optical data by the following equation <sup>8</sup> *g* 2.0023 where ∆ is the energy of the transition of the perfect octahedral site. λ is 324 cm-1 for free Ni2+ ion.
