Inverse isotope effects and models for high-Tc superconductivity

A model for high-temperature superconductivity with a mass-independent electronic mechanism in conjunction with a moderate amount of electron-phonon coupling has previously been shown to be inconsistent with experimental constraints on Tc, the isotope effect exponent, and the electron-phonon coupling. The present work allows for an electronic mechanism with an inverse isotope effect. In this case, the model is consistent with the experimental constraints.