 According to the frequency interpretation, the correspondence principle is defined as a statistical asymptotic agreement between the (quantum) frequency, \(\nu_{n' \rightarrow n''}\), of radiation emitted in a quantum jump of difference \(\tau\) from state \(n'\) to \(n''\) and the (classical) frequency \((\omega_{\tau})\) in the \(\tau\)th harmonic of the classical motion in the \(n'\) stationary state, namely