Theoretical studies on magnetic interaction in one-dimensional CunBrm (SÂ =Â 1/2) chains

Theoretical calculations for molecular-based magnetic materials have been carried out and successfully revealed magnetic interaction. Recently, Sugimoto and his co-workers reported synthesis and experimental studies for salts of TTF-derivative donors and CunBrm (S = 1/2) chains. In these crystals, their magnetic properties depend on structure changing. In this paper, we focus on magnetic interaction in one- dimensional CunBrm chains. Here, we introduced the universal model structure for their real crystals and four parameters (r, a, b and c) in it can fix the structure. The Jab values under each parameter value were studied by using of UHF, UB3LYP and UCCSD(T) methods. Magnetic interactions in all shapes of CunBrm chains were investigated.