  We propose a mechanism of intrinsic spin Hall effect (SHE). In this
mechanism, local orbital angular momentum (OAM) induces electron position shift
and couples with the bias electric field to generate orbital Hall effect (OHE).
SHE then emerges as a concomitant effect of OHE through the atomic spin-orbit
coupling. Spin Hall conductivity due to this mechanism is estimated to be
comparable to experimental values for heavy metals. This mechanism predicts the
sign change of the spin Hall conductivity as the spin-orbit polarization
changes its sign, and also correlation between the spin Hall conductivity and
the splitting of the Rashba-type spin splitting at surfaces.
