We present an ab-initio and analytical study of the Jahn-Teller effect in two diluted magnetic semiconductors (DMS) with d4 impurities, namely Mn-doped GaN and Cr-doped ZnS. We show that only the combined treatment of Jahn-Teller distortion and strong electron correlation in the 3d shell may lead to the correct insulating electronic structure. Using the LSDA+U approach we obtain the Jahn-Teller energy gain in reasonable agreement with the available experimental data. The ab-initio results are completed by a more phenomenological ligand field theory.
@article{arxiv.1003.0365,
title = {Electronic structure and Jahn-Teller effect in GaN:Mn and ZnS:Cr},
author = {F. Virot and R. Hayn and A. Boukortt},
journal= {arXiv preprint arXiv:1003.0365},
year = {2015}
}