STRETCHING VIBRATIONS AND STRUCTURE OF (HF)(N) (N=4-8) CLUSTERS

IR spectra of 24 structural isomers of (HF)(n) (n = 4-8) clusters were calculated in the framework of semiempirical theory of polyatomic mol ecule vibrations. Based on the results obtained and available experime ntal data it is proposed that (HF)(n) associates comprising 3-5-member ed cycles with attached monomeric HF units ore present in molecular be ams and gas phase. Ab initio calculations performed by the SCF method show the existence of local minima corresponding to such structures on the potential energy surface of (HF)(n) clusters (n = 4-6).