Role of hexadecapole deformation in fission potential energy surfaces of 240Pu

In this work, the multipole deformation-constrained Skyrme Hartree-Fock+BCS (SHF-BCS) calculations are implemented to obtain microscopic multi-dimensional potential energy surfaces for descriptions of fission of 240Pu. The SHF-BCS equation is solved in the axial-symmetric lattice space. The results show that the hexadecapole deformation is important at large deformations, and is related to issues of multiple solutions and discontinuities in potential energy surfaces. With a suitable disturbation of hexadecapole deformation β4, we can obtain a smooth 2-dimensional potential energy surface in (β2, β3) by parallel calculations. The constrained SHF-BCS calculation in the 3-dimensional deformation space of (β2, β3, β4) is also developed.