Investigations of the electron paramagnetic resonance parameters and the tetragonal local structure for (VCl6)4- coordination complex in MCl:V2+ (M=Na, K, Rb) systems

By simulating the electron paramagnetic resonance (EPR) and opticalspectra on the basis of the 120$times $120 complete energy matrix,this paper determines the local lattice structure parameters $R_1 $and $R_2 $ for MCl:V$^{2 + }$ (M=Na, K, Rb) systems at 77,K, 195,Kand RT (room temperature 295,K or 302,K), respectively. Thetheoretical results indicate that there exists a compresseddistortion in MCl:V$^{2 + }$ systems. Meanwhile, it finds that thestructure parameters $R_1 $, $R_2 $ and $left| {Delta R} right|$($ = R_1 - R_2 )_{ }$ increase with the rising temperature.Subsequently, from the analysis it concludes that the relation ofEPR parameter $D$ {vs.} $Delta R$ is approximately linear. Finally,the effects of orbital reduction factor $k$ on the $g$ factors forthe three systems have been discussed.