<math>\zeta</math> and <math>\Psi</math> are parameters that enable the free precession frequencies to be written in a more concise form (equation (12)).<br>
Note that in reference 2 ([http://dx.doi.org/10.1016/S0076-6879(01)39315-1 10.1016/S0076-6879(01)39315-1]), in equation 25, the definition used for <math>\tau_{\textrm{CP}}</math> is twice that used in this work but is otherwise identical.
The paper equation 50, needs following definitions
== Parameters ==