Nuclear Coulomb energy ($E_C\simeq a_C{Z}^2/A^{1/3}$)

Nuclear Coulomb energy is the positive electrostatic mass-energy contribution from proton repulsion in a nucleus. A uniform-charge model gives scaling $Z^2/R$, and approximately constant nuclear density gives $R\propto A^{1/3}$. It reduces conventional positive nuclear binding energy.