OH in vitreous silica

Abstract
The dielectric echo experiments are also analysed in detail, and it is shown that the tunnelling model can provide a semiquantitative explanation of the results. A more precise comparison between experiment and expectation is difficult because of the complexity of the problem, both from the experimental point of view and from that of the theory, which involves several additional factors not present in the magnetic case. However, the conclusion of the paper is that OH group rotation can provide a precise microscopic model for the effects of this impurity in vitreous silica.