ENDOR STUDY OF RBCL-S2-

A recent EPR study revealed an exceptionally well resolved superhyperf ine structure in the spectrum of RbCl: S2- for some specific orientati ons of the magnetic field. In this work a complete angular variation o f two sets of Rb-85 and Rb-87 ENDOR transitions is presented. The corr esponding hyperfine and nuclear quadrupole coupling tensors were deter mined. The orientation of the principal axes of these tensors is in ag reement with the overall D2h symmetry of the S2- ion in the crystal. T he ENDOR results can be explained only by assuming a monovacancy model , i.e. S2- replacing a single Cl-. The earlier EPR results are in perf ect agreement with the present ENDOR analysis.