Angular autocorrelation functions in molecular crystals: application to nuclear magnetic resonance relaxation and Raman spectra

摘要

the Theory of hindered molecular motion (HMM) in crystals, extended by taking the molecular site symmetry into account, is used in the calculation of the angular autocorrelation functions (ACFs). The basic model of motion involves a molecular rearrangement by means of random angular jumps of an intramolecular vector according to a crystallographic point symmetry group G between the potential wells in which the probability density of the vector orientation is continuously distributed over the angles.