Theoretical study of the magnetic exchange interaction in catena-μ-Tris[oxalato(2-)-O1,O2;O3,O4]-dicopper complex with interlocked helical chains

► Estimates of magnetic couplings in an extended structure with Cu bridged by oxalato. ► Determination of the magnetic structure based on the calculated magnetic couplings. ► Calculation of the magnetic susceptibility curve from the local magnetic couplings.