H^{QM/MM} =
H^{QM}_e-\sum_i^n\sum_J^M\frac{e^2Q_J}{4\pi\epsilon_0r_{iJ}}+\sum_A^N\sum_J^M\frac{e^2Z_AQ_J}{e\pi\epsilon_0R_{AJ}},
-# where :math:`n` and :math:`N` are the number of electrons and nuclei
+ where :math:`n` and :math:`N` are the number of electrons and nuclei
in the QM region, respectively, and :math:`M` is the number of
charged MM atoms. The first term on the right hand side is the
original electronic Hamiltonian of an isolated QM system. The first
E_{tot} = E_{I}^{QM}
+E_{I+II}^{MM}-E_{I}^{MM},
-# where the subscripts I and II refer to the QM and MM subsystems,
+ where the subscripts I and II refer to the QM and MM subsystems,
respectively. The superscripts indicate at what level of theory the
energies are computed. The ONIOM scheme has the advantage that it is
not restricted to a two-layer QM/MM description, but can easily