  We argue that in the ensemble Monte Carlo approach, the spin decoherence
caused by electron-electron interactions in n-type bulk GaAs at room
temperature, according to Dyakonov-Perel theory, is mainly induced by the
electron density while electron-electron scattering itself does not directly
affect spin lifetime but instead influences it through any energy dependence of
other scattering mechanisms as typically expected in the case of the electron
mobility. Therefore, our analysis, which is strongly supported by Bayesian
Occam's razor, reconciles the semiclassical Monte Carlo approach with the novel
computational first-principles tool recently proposed by Xu, Habib,
Sundararaman and Ping.
