Nuclear shape isomers

We calculate potential-energy surfaces as functions of spheroidal (epsilon(2)), hexadecapole (epsilon(4)), and axial-asymmetry (gamma) shape coordinates for 7206 nuclei from A = 31 to A = 290. We tabulate the deformations and energies of all minima deeper than 0.2 MeV and of the saddles between all pairs of minima. The tabulation is terminated at N = 160. Our study is based on the FRLDM macroscopic-microscopic model defined in ATOMIC DATA AND NUCLEAR DATA TABLES [P. Moller, J.R. Nix, W.D. Myers, W.J. Swiatecki, At. Data Nucl. Data Tables 59 (1995) 185]. We also present potential-energy contour plots versus epsilon(2) and gamma for 1224 even-even nuclei in the region studied. We can identify nuclei for which a necessary condition for shape isomers occurs, namely multiple minima in the calculated potential-energy surface. We find that the vast majority of nuclear shape isomers occur in the A = 80 region, the A = 100 region, and in a more extended region centered around Pb-208. A calculated region of shape isomers that has so far not been extensively explored is the region of neutron-deficient actinides north-east of (208)pb. (C) 2011 Elsevier Inc. All rights reserved.