  The paper presents the results of three-dimensional (3D) modelling of the
structure and the emission of accretion columns formed above the surface of
accreting strongly magnetized neutron stars under the circumstances when a
pressure of the photons generated in the column base is enough to determine the
dynamics of the plasma flow. On the foundation of numerical radiation
hydrodynamic simulations, several 3D models of accretion column are
constructed. The first group of the models contains spatially 3D columns. The
corresponding calculations lead to the distributions of the radiation flux over
the sidewalls of the columns which are not characterized by axial symmetry. The
second group includes the self-consistent modelling of spectral radiative
transfer and two-dimensional spatial structure of the column, with both thermal
and bulk Comptonization taken into account. The changes in the structure of the
column and the shape of X-ray continuum are investigated depending on physical
parameters of the model.
