  We study the origin of the intrinsic spin Hall conductivity (SHC) and the
d-orbital Hall conductivity (OHC) in Pt based on a multiorbital tight-binding
model with spin-orbit interaction. We find that the SHC reaches 1000
\hbar/e\Omega cm when the resistivity \rho is smaller than ~10 \mu\Omega cm,
whereas it decreases to 300 \hbar/e\Omega cm when \rho ~ 100 \mu\Omega cm. In
addition, the OHC is still larger than the SHC. The origin of huge SHE and OHE
in Pt is the large ``effective magnetic flux'' that is induced by the
interorbital transition between d_{xy}- and d_{x2-y2}-orbitals with the aid of
the strong spin-orbit interaction.
