Study of the potential energy of 'octupolly' deformed nuclei in a multidimensional deformation space

The collective potential energy of even-even 'octupolly' deformed nuclei is studied in a multidimensional deformation space in both radium and barium regions. This energy is calculated by the macroscopic-microscopic method, with the Yukawa-plus-exponential model taken for the macroscopic part and the Strutinski shell correction (based on the Woods-Saxon single-particle potential) used for the microscopic part of the energy. The deformations βλ of all multipolarity degrees: λ = 2, 3, ..., 7 (or even 8) are treated as independent variables. The multipolarities: λ = 5, 6 and 7, usually omitted or treated in an average way up to now, are found to be important for the properties of the nuclei. (orig.)