THE ROTATIONAL TUNNELING DYNAMICS OF THE AMMONIUM ION IN AMMONIUM-NITRATE

The rotational dynamics of the NH3D+ ion in ammonium nitrate (phase V) have been studied at low temperatures. Each of the four N-D stretching bands has been irradiated with an infrared laser, and this irradiation causes rotation of the ions with a quantum efficiency of about 10(-3). With the laser off, the rates of rotation in the vibrational ground state are determined. The four sets of data: the relative rates to different orientations in the excited state, the rates in the ground state, the hydrogen bond lengths determined by diffraction methods, and the frequencies of the N-D stretches do not correlate in a simple manner with one another.