The dynamic Jahn—Teller effect in octahedrally co-ordinated d 9 ions

The nature of the electronic-vibrational states of a d9 ion in an octahedral complex is discussed in term s of an adiabatic model in which th e electronic motion follows the nuclear motion exactly. Expressions for the g-values and the hyperfine structure parameters of the e.s.r. spectrum at high and low temperatures are derived. Relaxation processes and other effects due to the complex being part of a crystal are discussed.