The formation of a long-range Jahn-Teller distortion in undoped manganites is studied within the dynamical mean-field theory taking both electron-phonon and electron-electron interactions into account. We find that the observed insulating behavior at temperatures above the Jahn-Teller transition and the bond-length changes below it can most naturally by explained by assuming a strong electronic repulsion and a rather weak electron-phonon coupling.
@article{arxiv.cond-mat/9810185,
title = {Jahn-Teller distortion and electronic correlation effects in undoped manganese perovskites},
author = {Patrizia Benedetti and Roland Zeyher},
journal= {arXiv preprint arXiv:cond-mat/9810185},
year = {2009}
}