  We present a detailed study of the imaginary and real parts of the
spin-susceptibility of silicene which can be generalized to other buckled
honeycomb structure. We find that while the off-diagonal components are
non-zero in individual valleys, they add up to zero upon including
contributions from both the valleys. We investigate the interplay of the
spin-orbit interaction and an external electric field applied perpendicular to
the substrate and find that although the xx and yy components of the
susceptibility are identical, they differ from the zz-component. The external
electric field plays an important role in modifying the allowed inter-subband
regions. In the dynamic limit, the real part of the susceptibility exhibits
log-divergence, position of which can be tuned by the electric field and
therefore has implications for spin-collective excitations. The effect of the
electric field on the static part of the susceptibility and its consequence for
the long distance decay of the spin-susceptibility have been explored.
