  Exceptionally displaceable ions, evidenced by huge ratios of materials static
to high-frequency dielectric constants, enable short-range electron-phonon
interactions to stabilize large planar bipolarons. These large bipolarons are
compact and strongly bound. By contrast, very diffuse and weakly bound large
bipolarons result without the electron-phonon interactions short-range
component. Cuprates superoxygen bipolarons are centered on four inward relaxing
oxygen anions circumscribed by four outward relaxing copper cations.
Concomitant oxygen to copper charge transfer converts them to spinless Cu1+
cations. The planar d symmetry of superoxygens' groundstate molecular orbital
tracks the superoxygens' predominant zeropoint radial vibrations. These large
bipolarons distinctive charge transport, absorption, magnetism, local atomic
vibrations, condensation into a liquid and subsequent high-temperature
superconductivity are consistent with cuprate superconductors' long-established
unusual properties.
