Submillimeter spectrum of NH3−H2O dimer in its equilibrium gas phase

The first observation of the microwave spectrum of the NH3−H2O molecular complex in its equilibrium gas phase is reported. Earlier, the spectrum of NH3−H2O was observed only in nonequilibrium cold supersonic molecular beams. As in the previous paper [1] dealing with the observation of the equilibrium spectrum of HF-HF dimer, we use a submillimeter spectrometer with a BWT and acoustic detector and a cooled absoprtion cell. The submillimeter line frequencies continuing the series known from the beam investigations have been measured. New series, which obviously correspond to the higher states of the dimer, have been detected. The primary results of the analysis of the dimer spectrum together with the earlier data are presented.