## B. Fission barrier 

In Fig. 10, the potential energy curves for $^{240}$Pu as functions of the quadrupole defor- mation β$_{2}$ are shown. The dashed and solid lines correspond to the axially-symmetric and the triaxial calculations with PC-PK1, respectively. In the case of triaxial calculation, the solid line refers to the minima for each β for the potential energy surface (PES) in the β − γ plane. For comparison, the axially-symmetric result given by PC-F1 is also included. 

It is found that the PC-PK1 provides not only a good description for the deformation of the ground state [56] but also the energy difference between the ground-state and the shape isomeric state [57]. Furthermore, after including the triaxiality, as shown in Fig 10, the fission barrier given by PC-PK1 is in agreement with the empirical value [58]. It should be noted that the pairing correlation plays an important role in the description of fission barrier. Discussion on the dependence of the fission barrier height on the pairing correlations can be found in Ref. [59]. 

## VII. NUCLEAR EXCITED PROPERTIES 

As a test of the new parameter set PC-PK1 in the description of nuclear spectroscopic properties for low-lying excitation states, the collective excitation spectra and transition probabilities in $^{150}$Nd as well as the characteristic collective observables for Nd isotopes will be calculated starting from a five-dimensional collective Hamiltonian in which the parameters are determined by constrained self-consistent RMF calculations for triaxial shapes [60–62]. 

In Fig. 11, the excitation energies and B ( E 2; L + 1 → [ L − 2] + 1 ) values for the yrast states in $^{150}$Nd predicted by PC-PK1 are shown in comparison with data [63, 64] and those by DD- PC1 and PC-F1. It can be seen that all the effective interactions provide similar excitation energies and intraband B ( E 2) values for the yrast band and reproduce the data quite well. 

In Fig. 12, the characteristic collective observables R$_{4}$$_{/}$$_{2}$ = E (4 + 1 ) /E (2 + 1 ) and B ( E 2; 2 + 1 → 0 + 1 ) for Nd isotopes given by PC-PK1 are shown in comparison with data [63, 64] and those by DD-PC1 and PC-F1. It is found that all the parameter sets reproduce the data quite well. In particular, the calculations reproduce in detail the rapid increase of R$_{4}$$_{/}$$_{2}$ and B ( E 2) with the neutron number, i.e., from R$_{4}$$_{/}$$_{2}$ ∼ 1 . 9 and B ( E 2) < 30 W.u. in near spherical $^{144}$Nd to R$_{4}$$_{/}$$_{2}$ ∼ 3 . 3 and B ( E 2) > 150 W.u. in well-deformed $^{152}$Nd. 

