Experimental data and calculated parameters in FeS polymetallic centers in proteins

Abstract

 Covariance between J and B parameters and indetermination of the actual symmetry suggest caution in making general statements about their values in Fe_nS_n centers. The Fe₄S₄ ³⁺ case is further complicated by electronic isomerism and lack of information on the actual symmetry. Electronic ground states and relative J and B values are discussed in the light of hyperfine coupling values.