Toward <i>ab initio</i> charge symmetry breaking in nuclear energy density functionals

We propose a new approach to determine the strength of charge symmetry breaking (CSB) term in framework nuclear density functional theory. It is shown that once ab initio calculations are available including accurate description isospin terms medium and heavy nuclei, mass difference mirror nuclei as well neutron-skin thickness doubly-closed-shell can be used constrain CSB interaction with an uncertainty less than $ 6 \, \% $, separately from other forces. This method opens vista energy functionals.