  Dependence of the kinetic energy term of the collective nuclear Hamiltonian
on collective momentum is considered. It is shown that the fourth order in
collective momentum term of the collective quadrupole Hamiltonian generates a
sizable effect on the excitation energies and the matrix elements of the
quadrupole moment operator. It is demonstrated that the results of calculation
are sensitive to the values of some matrix elements of the quadrupole moment.
It stresses the importance for a concrete nucleus to have the experimental data
for the reduced matrix elements of the quadrupole moment operator taken between
all low lying states with the angular momenta not exceeding 4.
