  Little is known about the spin-flip diffusion length $l_{\rm sf}$, one of the
most important material parameters in the field of spintronics. We use a
density-functional-theory based scattering approach to determine values of
$l_{\rm sf}$ that result from electron-phonon scattering as a function of
temperature for all 5d transition metal elements. $l_{\rm sf}$ does not
decrease monotonically with the atomic number Z but is found to be inversely
proportional to the density of states at the Fermi level. By using the same
local current methodology to calculate the spin Hall angle $\Theta_{\rm sH}$
that characterizes the efficiency of the spin Hall effect, we show that the
products $\rho(T)l_{\rm sf}(T)$ and $\Theta_{\rm sH}(T)l_{\rm sf}(T)$ are
constant.
