Geometrical dependence of molecular-frame photoelectron emission from H2+

We study the photoemission spectra of the hydrogen molecular ion for various geometrical arrangements. For different angles between the internuclear axis and the polarization vector, we calculate the angular distribution and analyze the results in terms of the symmetries and partial-wave contributions to the spectra. Contrary to previous studies we find that the angular distribution is not aligned with the internuclear axis or the polarization vector. The alignment is determined by the coherent superposition of σ→σ and σ→π transition amplitudes and by the relative contributions from the different partial waves, strongly dependent on the photoelectron energy