The binding energies and electron momentum distributions of the five valence orbitals of have been measured at high momentum resolution. The measured binding energy spectrum has been compared favourably with the results of previously published experimental data, theoretical calculations and outer-valence Green function method calculation of this work. The measured momentum profiles have been quantitatively compared with momentum distributions predicted by Snyder and Basch molecular wavefunctions, self consistent field (SCF) wavefunctions up to the near-Hartree-Fock limit, density functional theory calculations and experimental data (Dey et al 1976 J. Electron Spectrosc. Relat. Phenom. 9 397). They are found to be in excellent agreement with Snyder and Basch molecular wavefunctions and density functional theory calculations, especially for the orbital. The density maps for oriented molecule in position and momentum space are presented.