and Sektion Physik d e r Kar,l-Marx-Universitat , Leipzig (b) 2+ Ligand Hyperfine Structure of Mn in ZnSe as Calculated by EHT-SCCC , Scattered-Wave, and LCAO Methods BY S.W. BIERNACKI (a), M. HAMERA (a), and S. WARTEWIG (b)One of the characteristics of iron group ions resulting from their incorporation a s impurities into crystals is the delocalization of the d electrons into neighbouring atoms, and it i s known /1/ that hyperfine interactions with nuclei neighbouring the impurity a r e mostly due to this delocalization. Here we report the numerical estimations of the ligand hyperfine structure parameters of ZnSe:Mn 2+ based on three models, namely: EHT-SCCC (Extended Hiickel Theory-Self-consistent Charge and Configuration), scattered-wave, and LCAO methods.