Investigation of electronic interactions in solid hydrogen fluoride

Abstract

Intermolecular interactions in solid hydrogen fluoride are studied by the combined quantum chemical and X- ray diffraction method. The structure of crystalline HF is modeled by (HF)n chains (n =2, 3,...,20, by an (HF)45 cluster consisting of five (HF)9 chains, and by an (HF)108 cluster consisting of twelve (HF)9 chains with nearly zero dipole moment. The quantum chemical calculations of the clusters are performed by the semiempirical AM1 method, which is most suitable for electronic structure investigations of hydrogen fluoride, as shown by comparing the X- ray experimental and theoretical spectra. The theoretical X- ray spectra are also compared with the experimental FKα spectra of gaseous and solid hydrogen fluoride. For more detailed studies of electronic interactions in crystalline HF, fragrnent analysis of MOs of the clusters with respect to the MOs of the central molecule is carried out.