On the angular distributions of molecular photoelectrons: dipole cross-sections for fixed-in-space and randomly

New theoretical expressions are devised employing a dynamical perspective f or photoionization cross-sections differential in electron ejection angles for both fixed-in-space and randomly oriented molecules, and comparisons ma de with K-shell ionization measurements in molecular nitrogen. Closed-form, cross-sectional expressions are obtained in the dipole limit in terms of m olecular body-frame transition moments and related normalized angular-distr ibution amplitudes which can be calculated employing interaction-prepared s tates without reference to specific scattering boundary conditions, and whi ch reduce to more familiar atomic expressions in appropriate limits. (C) 20 01 Published by Elsevier Science B.V.