Structural chemistry and high-temperature superconductivity.

Phenomenological trends in superconducting transition temperature T sub c and energy gap E sub g as measured in many tunneling experiments are discussed for ternary metallic Cu oxides. Available data are consistent with the Bardeen-Frolich electron- phonon mechanism and the Bardeen-Cooper-Schrieffer microscopic theory. The role of Cu oxidation is discussed in the context of the mechanical stability of the perovskite-like lattice structure.