CNDO and INDO MO calculations of a few properties of rubredoxins

The CNDO and INDO MO calculations have been performed on the oxidised and reduced species of rubredoxins using Clack, Hush and Yandle's parameterisation scheme for the transition metal complexes in conjunction with Pople and Nesbet's open-shell UHF method in an attempt to elicit information on the geometry of the conformation of the iron environment. The properties like isotropic and anisotropic hyperfine coupling constants and quadrupole splitting have been calculated and compared with the corresponding experimental values. The results suggest that both the oxidised and reduced species have the iron atoms attached to four sulphur atoms situated as pairs in two perpendicular planes as a result of a highly distorted tetrahedral arrangement © 1980 Indian Academy of Sciences.