Octupole deformations in the very extended nuclear shapes of the A ∼ 180 region

Energy surfaces in the A ∼ 180 region have been investigated on an extended grid in a four-dimensional deformation space consisting of quadrupole, octupole, hexadecapole and necking deformations. A lowering in the energy surface of several MeV caused by octupole deformation, is found for many nuclides in the vicinity of 176W at very large values of the elongation and necking. Octupole softness of the known extended minima is found to be quite similar in most instances.