  A method is developed to derive simple relations among the reduced matrix
elements of the quadrupole operator between low-lying collective states. As an
example, the fourth order scalars of Q are considered. The accuracy and
validity of the proposed relations is checked for the ECQF Hamiltonian of the
IBM-1 in the whole parameter space of the Casten triangle. Furthermore these
relations are successfully tested for low-lying collective states in nuclei for
which all relevant data is available.
