ELECTRON MOMENTUM SPECTROSCOPY OF METHYLAMINE

The complete valence shell electron separation energy spectra and mome ntum distributions are measured for methylamine by high-resolution ele ctron momentum spectroscopy at a total energy of 1500 eV. Many-body ca lculations of the separation energies and spectroscopic factors using Green's function methods are carried out and compared with the experim ental data. The measured momentum distributions are compared with thos e calculated in the plane wave impulse approximation (PWIA) formalism using an SCF orbital wavefunction which we constructed from a basis se t of states that consisted of (10s, 6p, 1d)/[5s, 3p, 1d] for the carbo n and nitrogen atoms and (5s, 1p)/[3s, 1p] for each hydrogen atom. The agreement between the measured momentum distributions and the present PWIA-SCF orbital momentum distributions is, in general, fair, althoug h for the outermost valence 7a' state the SCF wavefunction underestima tes the density at low momentum. The inner valence 4a' and 3a' orbital s are found to be severely split by the final state correlation effect s. The agreement between the measured and calculated spectroscopic fac tors and separation energies is quite good, although the measured sepa ration energy spectra contain significant strength up to 41 eV, this s trength being mainly of 4a' and 3a' origin.