ROTATIONAL SPECTRUM AND STRUCTURE OF HCP

The ground state rotational spectra of HCP, (HCP)-C-13, DCP, and (DCP) -C-13 have been measured in the millimeter-wave and submillimeter-wave ranges. For HCP and DCP, the rotational spectra in the vibrationally excited states v(2) = 1, 2 and v(3) = 1 have also been analyzed. The e quilibrium structure has been calculated ab initio and experimentally redetermined. The derived structure is compared to those of the simila r molecules FCP and ClCP and its accuracy is discussed. The equilibriu m structure of FCP has also been redetermined by combining the experim ental rotational constants and ab initio calculations. (C) 1996 Academ ic Press, Inc.