EXPERIMENTAL AND THEORETICAL STUDIES OF HF DIMER

$^{1}$ J.M. Lisy, A. Tramer, M.F. Vernon and Y.T. Lee, J. Chem. Phys. 75, 4733 (1981). $^{2}$ A.S. Pine and W.F. Lafferty, J. Chem. Phys. 78, 2154 (1983).Author Institution: Department of Chemistry, University of IllinoisThe vibrational predissociation spectrum of HF dimer at low $(8 cm^{-1})$ $resolution,^{1}$ indicated the vibrational frequency of the hydrogen-bonded HF was approximately $3720 cm^{-1}$. In the high (1 MHz) gas-cell absorption $spectrum^{2}$ of $(HF)_{2}$, a band centered at $3868.079 cm^{-1}$ was determined to be due to the hydrogen-bonded HF. We have reinvestigated the $3720 cm^{-1}$ at higher $(0.7 cm^{-1})$ resolution and have confirmed that it is due to HF dimer. To resolve the two disparate results, an ab initio potential energy surface for HF dimer has been determined using a triple-zeta + polarization basis set, including configuration interaction at the approximate double substituted coupled cluster (ACCD) level. The results from the potential surface and experiments will be discussed