ELECTRON MOMENTUM DISTRIBUTIONS AND IONIZATION-ENERGY SPECTRA OF BORON-TRIFLUORIDE

The complete valence shell binding energy spectra and valence orbital electron momentum distributions for BF3 have been measured by (e, 2e) spectroscopy or electron momentum spectroscopy (EMS), at a total energ y of 1200 eV and using symmetric non-coplanar kinematics. Two SCF calc ulations, referred as SCF1 and SCF2 with the contracted basis of (9s5p 1d)/[4s2p1d] and (13s8p4d)/[7s4p4d] respectively, have been carried ou t. A Green's function calculation based on the SCF1 wavefunction has a lso been performed. The measured binding energy spectra from 11.5 to 5 5 eV are compared with the results of one-particle Green's function ca lculations for the ionization energies and their corresponding pole st rengths. The measured spherically averaged momentum distributions for the valence orbitals are quantitatively compared with theoretical calc ulations using the two SCF wavefunctions. In general, the SCF wavefunc tions do not describe the experimental data very well, particularly in the low-momentum region. In the outer valence region there is a good agreement between the calculated energies and pole strengths and the m easured ones. The 2e' and 3a1' in the inner valence region are strongl y split due to electron correlation and ion relaxation effects. The Gr een's function calculation, using the 2ph Tamm-Dancoff or ADC (3) appr oximation, underestimated the splitting in the inner-valence region.