  We study the spin-charge conversion mechanisms in a two-dimensional gas of
electrons moving in a smooth disorder potential by accounting for both
Rashba-type and Mott's skew scattering contributions. We find that quantum
interference effects between spin-flip and skew scattering give rise to
anisotropic spin precession scattering (ASP), a direct spin-charge conversion
mechanism that was discovered in an earlier study of graphene decorated with
adatoms [C. Huang \emph{et al.} Phys.~Rev.~B \textbf{94} 085414.~(2016)]. Our
findings suggest that, together with other spin-charge conversion mechanisms
such as the inverse galvanic effect, ASP is a fairly universal phenomenon that
should be present in disordered two-dimensional systems lacking inversion
symmetry.
