  The broken pair model has been developed earlier as an useful approximation
to the nuclear shell model for even-even nuclei. It is extended and developed
here to include odd nuclei too. The model is then applied successfully in the
Zr region, using two different sets of matrix elements, the empirical and the
realistic sussex ones. The broken pair model results show a considerable
agreement with the shell model results wherever available and with the
experimental data where shell model calculations are not performed yet.
