R FCasten, PRl54, 1991(1985) Ba Ce Nd Sm Gd Dy Er Yb 2487296120144168192 N=90 28 86 N 5658606264666870 0612182430364248 FIG.1.NpN, systematics for the A=150 region. The boson product NN,N,N,/4 is also given. C1985 The American Physical Society 1991 For even-even nuclei E,,E,E,R=EE2,B(E2,01→21)1 1 1 1 1 2 4 6 4 2 1 1 For even-even nuclei, E E E R E E B E + + + + + , , , / , ( 2,0 2 ) + + = → R.F.Casten, PRL54, 1991(1985)