Theoretical calculations under the scheme of WIEN2k computer package had been performed on the pristine compound LaOFeAs, as well as on LaO1-xFxFeAs. One factor crucial to the manifestation of superconductivity seems to be fluorine doping; hence we search for its effect. Paying close attention to Fe d-orbitals upon doping of F by O, at first, Fe d-orbitals have dz2 symmetry, changing gradually to something akin to dx2-y2 which seems more prone to conductivity than the former one. This issue agree with the accepted results happened in the copper-based high-temperature superconductors.
@article{arxiv.0811.3473,
title = {Fluorine effect in layered oxypnictide LaOFeAs},
author = {A. Reyes-Serrato and D. H. Galvan and G. Soto},
journal= {arXiv preprint arXiv:0811.3473},
year = {2008}
}