Models of stellar atmospheres are based on assumption of their plane-parallel or spherical symmetry. Violation of this assumption by tides and rotation in close binaries leads to incompatibility of hydrostatic and radiative equilibria. Improvement of model atmospheres in this respect is desirable for simulation of light curves and line profile changes. Moreover, atmospheres of
contact components of interacting binaries determine initiai conditions of dynamics of gaseous streams and in this way influence the behaviour of the binary system.