抄録
Effects of covalency on the nuclear magnetic resonance in ionic crystals are discussed on the basis of perturbation calculations. Formulas for the chemical shift, the I–I coupling and the quadrupolar relaxation time are derived. Using the degree of covalency deduced from the experimental values of the chemical shift, the coefficient of the I–I coupling and the quadrupolar relaxation time are estimated for some ionic crystals. It is shown that, when the degree of covalency is several percent, the quadrupolar relaxation time becomes much shorter than in pure ionic case. For instance, the relaxation time of Br in KBr, assuming the degree of covalency of 1 percent, is estimated to be 1 sec, which is only several times larger than the experimental value.
