E(5), X(5), and Prolate to Oblate Shape Phase Transitions in   Relativistic Hartree Bogoliubov Theory
  Relativistic mean field theory with the NL3 force is used for producing potential energy surfaces (PES) for series of isotopes suggested as exhibiting critical point symmetries. Relatively flat PES are obtained for nuclei showing the E(5) symmetry, while in nuclei corresponding to the X(5) case, PES with a bump are obtained. The PES corresponding to the Pt chain of isotopes suggest a transition from prolate to oblate shapes at 186-Pt. 
R. Fossion, D. Bonatsos, G. A. Lalazissis