Аннотации:
It is shown that the contributions of two-stage resonance processes in which the state of an electron does not vary as a result of nuclear relaxation are not taken into account in the usual equations for the rate of nuclear relaxation by paramagnetic impurities. In particular, these transitions yield a contribution precisely equal to the contribution of cross-over processes. Nuclear relaxation due to a magnetic ion with singlet ground level in which these processes are particularly great is investigated. © 1977 Plenum Publishing Corporation.