# Modification of mass formula by considering isospin effects 

Ning Wang, 1, ∗ Min Liu, 2, 1 and Xizhen Wu 3 

$^{1}$Department of Physics, Guangxi Normal University, Guilin 541004, P. R. China 

2 College of Nuclear Science and Technology, Beijing Normal University, Beijing, 100875, P. R. China 

$^{3}$China Institute of Atomic Energy, Beijing 102413, P. R. China 

## Abstract 

We propose a semi-empirical nuclear mass formula based on the macroscopic-microscopic method in which the isospin and mass dependence of model parameters are investigated with the Skyrme energy density functional. The number of model parameters is considerably reduced compared with the finite range droplet model. The rms deviation with respect to 2149 measured nuclear masses is reduced by 21%, falls to 0.516 MeV. The new magic number N = 16 in light neutron-rich nuclei and the shape coexistence phenomena for some nuclei have been examined with the model. The shell corrections of super-heavy nuclei are also predicted. 

