The role of hydrogen-bonds for electronic properties in transition-metal compounds

The role of hydrogen-bonds playing for electronic properties is studied from the theoretical viewpoint in two kinds of transition-metal (TM) compounds: halogen-bridged mixed-valence TM-complexes (type I) and perovskite-type hole-doped TM-oxides under hydrogen-containing atmosphere (type II). It is discussed that the correlation among charge-density-wave chains (type I) and the electric conduction (type II) can be controlled by the proton motion on the hydrogen-bonds in these compounds.