By calculation and analysis of the bare conduction bands in a large number of hole-doped high-temperature superconductors, we have identified the energy of the so-called axial-orbital as the essential, material-dependent parameter. It is uniquely related to the range of the intra-layer hopping. It controls the Cu 4s-character, influences the perpendicular hopping, and correlates with the observed Tc at optimal doping. We explain its dependence on chemical composition and structure, and present a generic tight-binding model.
@article{arxiv.cond-mat/0012051,
title = {Band-structure trend in hole-doped cuprates and correlation with Tcmax},
author = {E. Pavarini and I. Dasgupta and T. Saha-Dasgupta and O. Jepsen and O. K. Andersen},
journal= {arXiv preprint arXiv:cond-mat/0012051},
year = {2009}
}