where \(\alpha\) is the index of an atom, \(\mathbf{R}_{\alpha}\) is the
position of the atom, and \(Z_{\alpha}\) is the nuclear charge of the
atom. The first term is the direct contribution to the total ESP from
the monomers, the second term is a two-body correction from the dimers,
and the third term is the ESP due to the atomic nuclei. The more
detailed information about this equation can be found in the previous
paper.33
The pESP can be introduced similarly to the pEDN, i.e.,