  In the last decades, dynamical mean-field theory (DMFT) and its diagrammatic
extensions have been successfully applied to describe local and nonlocal
correlation effects in correlated electron systems. Unfortunately, except for
the exact solution, it is impossible to fulfill both the Pauli principle and
conservation laws at the same time. Consequently, fundamental observables such
as the kinetic and potential energies are ambiguously defined. In this work, we
propose an approach to overcome the ambiguity in the calculation of the
potential energy within the ladder dynamical vertex approximation (D$\Gamma$A)
by introducing an effective mass renormalization parameter in both the charge
and the spin susceptibility of the system. We then apply our method to the
half-filled single-band Hubbard model on a three-dimensional bipartite cubic
lattice. We find that: (i) at weak-to-intermediate coupling, a reasonable
modification of the transition temperature $\TN$ to the antiferromagnetically
ordered state with respect to previous ladder D$\Gamma$A calculations without
charge renormalization. This is in good agreement with dual fermion and Monte
Carlo results; (ii) the renormalization of charge fluctuations in our new
approach leads to a unique value for the potential energy which is
substantially lower than corresponding ones from DMFT and non-self-consistent
ladder D$\Gamma$A; and (iii) the hierarchy of the kinetic energies between the
DMFT and the ladder D$\Gamma$A in the weak coupling regime is restored by the
consideration of charge renormalization.
