The nuclear binding energy is defined as the energy required to break up a given nucleus
into its constituent parts of \( N \) neutrons and \( Z \) protons. In terms of the atomic masses \( M(N, Z) \) the binding energy is defined by
$$
BE(N, Z) = ZM_H c^2 + Nm_n c^2 - M(N, Z)c^2 ,
$$
where \( M_H \) is the mass of the hydrogen atom and \( m_n \) is the mass of the neutron.
In terms of the mass excess the binding energy is given by
$$
BE(N, Z) = Z\Delta_H c^2 + N\Delta_n c^2 -\Delta(N, Z)c^2 ,
$$
where \( \Delta_H c^2 = 7.2890 \) MeV and \( \Delta_n c^2 = 8.0713 \) MeV.