Electron angular distribution in photoionization of spatially oriented linear molecules for different experimental geometries

On the basis of the general expression for angular distribution of electrons resulting from photoionization of space-oriented molecules one derived simplified formulae for a special case of photoionization of linear molecules with the centre of inversion in Σ state with formation of molecular ions in Σ- and Π-states. For different versions of the geometric arrangement of vectors guiding the angular distribution one derived simple formulae and carried out their comparison analysis. For different terms of the experimental measurement of angular dependences of electron escape one may determine the values of different matrix elements, phase differences and may separate processes resulting in ion formation in the states with different symmetry