  We show that combined electrostatic and radiative fields can greatly amplify
the directional properties, such as axis orientation and alignment, of
symmetric top molecules. In our computational study, we consider all four
symmetry combinations of the prolate and oblate inertia and polarizability
tensors, as well as the collinear and perpendicular (or tilted) geometries of
the two fields. In, respectively, the collinear or perpendicular fields, the
oblate or prolate polarizability interaction due to the radiative field forces
the permanent dipole into alignment with the static field. Two mechanisms are
found to be responsible for the amplification of the molecules' orientation,
which ensues once the static field is turned on: (a) permanent-dipole coupling
of the opposite-parity tunneling doublets created by the oblate polarizability
interaction in collinear static and radiative fields; (b) hybridization of the
opposite parity states via the polarizability interaction and their coupling by
the permanent dipole interaction to the collinear or perpendicular static
field. In perpendicular fields, the oblate polarizability interaction, along
with the loss of cylindrical symmetry, is found to preclude the wrong-way
orientation, causing all states to become high-field seeking with respect to
the static field. The adiabatic labels of the states in the tilted fields
depend on the adiabatic path taken through the parameter space comprised of the
permanent and induced-dipole interaction parameters and the tilt angle between
the two field vectors.
