  The SEHRS and SERS spactra of 4,4 - Bipyridine are analyzed on the base of
the Dipole-Quadrupole theory for two possible geometries of the molecule. It is
demonstrated that there appear strong lines caused by vibrations transforming
after a unit irreducible representation both for the geometry with D2 and D2h
symmetry groups, which may probably describe the symmetry properties of the
molecule. Appearance of these lines is associated with a strong quadrupole
light-molecule interaction, which arises in nano size rregions of sharp
roughness of the metal. In addition, there are the lines caused by
contributions from both the vibrations transforming after the unit irredicible
representations A or Ag and the representations B1 or B1u, respectively, which
describe transformational properties of the Ez component of the dipole moment,
which is perpendicular to the surface for both geometries. This result is
associated with a specific geometry of the molecule, when the indicated
vibrations can be nearly degenerated and can not be resolved by the SEHRS and
SERS spectra analysis. This issue is in a full compliance with the results of
the SEHRS and SERS Dipole-Quadrupole theory.
