Abstract
We have studied ESR, 1H NMR and 13C NMR in ternary graphite intercalation compounds C8KH0.61 prepared from the highly oriented pyrolitic graphite (HOPG). Although it has been controversial whether the hydrogen atom has a localized moment, our experiment proves non-existence of the localized moment. It is shown that the absorbed hydrogen molecules are dissolved into an atomic state and that the hydrogen atoms have a metallic character. The electronic state of hydrogen atoms and their geometrical arrangement are discussed.