  Within the approximation of dominant charging collisions the explicit
microscopic calculations of the Fokker-Planck kinetic coefficients for
highly-charged grains moving in plasma are performed. It is shown that due to
ion absorption by grain the friction coefficient can be negative and the
appropriate threshold value of the grain charge is found. The stationary
solutions of the Fokker-Planck equation with the velocity dependent kinetic
coefficient are obtained and the considerable deviation of such solutions from
the Maxwellian distribution is established.
