Initial values of parameters for variable moment of inertia models

The long write-up summarizes the procedure for determining the initial values of parameters for the fitting of rotational spectra in even-even nuclei. The functional form of the fitting is: Esub(I) = C2 (Jsub(I) - J0)2 + C3 (Jsub(I) - J0)3 + C4 (Jsub(I) - J0)4 + ... with the condition dEsub(I)/dJsub(I) = 0, where Esub(I) and Jsub(I) are the excitation energy and moment of inertia at a certain angular momentum I, respectively, and Csub(i) and J0 are the parameters of interest. While the determination of these parameters can be done following several standard fitting procedures, in all cases (since we always have to solve a nonlinear system of equations), there is a great sensitivity to the initial values of these parameters. The purpose of this paper is to determine initial values suitable for any standard fitting procedure, by using an approximate solution of the problem. (orig.)