  The superdeformation (SD) in non-rotating states is studied with the HF+BCS
method using the Skyrme interaction. In applying the BCS theory, the seniority
pairing force is employed, of which strengths are determined in order to
reproduce the empirical pairing gap formula, $\bar{\Delta} = 12 A^{-1/2}$ MeV,
through a smooth level density obtained in the Thomas-Fermi approximation.
Properties of superdeformation are investigated by calculating potential energy
surfaces (PES) for various sets of the pairing force strengths and the Skyrme
force parameter for 194Hg and 236,238U. The best results are obtained using
both the SkM* force and the pairing force strength determined in this paper. By
making use of this set of forces, a systematic calculation of SD states is
carried out extensively for even-even nuclei for 20 <= Z <= 82. From our
calculation, the barriers preventing the decay into the normally deformed
states are about twice as high as those predicted by Krieger et al., who used
the same Skyrme interaction but a pairing force stronger than ours. The
differences of the present results from the Nilsson-Strutinsky calculation are
analyzed.
