VALENCE SHELL PHOTOIONIZATION DYNAMICS CALCULATIONS FOR ORIENTED PF3 MOLECULES

Photoelectron angular distributions (PADs) from the ionization of fixe d-in-space, oriented PF3 molecules have been computed using the CMS-X alpha method. These molecule frame distributions are richly structured and varied with a high harmonic content. Interference terms between o dd- and even-partial waves create orientation in the PAD, and in some instances such oriented PADs may undergo a dramatic inversion, or reve rsal of direction, at a shape resonance. This phenomenon is attributab le to the rapid rise in scattering phase of a single resonant partial wave component. A previously observed reversal in the experimental PF3 (A) over tilde band correlated photoelectron photofragment ion recoil direction can be understood in these terms. Good agreement is found b etween the experimental and; calculated molecule frame anisotropy for ionization of the 4e orbital over a range of electron kinetic energies . The assignment of the (A) over tilde band is thereby clarified, and the presence of a 4e-->ka(1)(sigma) shape resonance at similar to 3 e V can be confirmed without the necessity to scan through the resonance energy. Other shape resonances in the range 0-25 eV are identified by the calculations; all an investigated and the resonant behavior is sc rutinized with the assistance of continuum eigenchannel plots. In this manner different trapping mechanisms can be visualized and the locali zation of the continuum scattering functions related to virtual atomic and molecular orbitals embedded in the ionization continuum. (C) 1995 American Institute of Physics.