  It is widely accepted that: (i) the angle-resolved photoemission spectroscopy
(ARPES) data produce evidences for the opening of a d-wave pairing gap in
cuprates compounds described at low energies and temperatures by a BCS theory,
and (ii) the basic pairing mechanism arises from the antiferromagnetic exchange
correlations, but the charge fluctuations associated with double occupancy of a
site also play an essential role in doped systems. The simplest model that is
consistent with the two statements is the $t$-$U$-$V$-$J$ model. We have shown
that the inelastic neutron scattering data on $YBa_2Cu_3O_{6.7}$ [Phys. Rev.
Lett. \textbf{83}, 608 (1999)] combined with the corresponding ARPES data allow
us to obtain the strength of the on-site repulsive interaction $U$, as well as
the strengths of the spin-independent attractive interaction $V$ and the
spin-dependent antiferromagnetic interaction $J$.
