The Jahn-Teller effect in the electron momentum spectroscopy of ammonia

The 1e and 3a1 bands of the ammonia molecule have been studied using the high-resolution electron momentum spectroscopy at impact energies of 1200 and 600 eV. Several slices of 1e and 3a1 bands in the different binding energy ranges were selected, and their electron-momentum distributions were carefully compared. The discernable difference among the distributions of the selected slices of the 1e band shows that the Jahn-Teller effect indeed influences the electron momentum distribution of the 1e orbital of ammonia.