Studies of the anion position parameter χ of the ternary semiconductor CuGaS2 by use of Ni+ ion probe

The anion position parameter χ of NiS4 cluster formed in the ternary semiconductor CuGaS2 by substitution of Ni+ for Cu+ has been determined by studying the optical spectra and EPR data for CuGaS2: Ni+. The result (χ≈0.263(1)) is consistent with the mean value of the X-ray measurement results reported in two groups of references and also with the calculated value obtained from the conservation of tetrahedral bonds (CTB) plus η=ηtet rule (where η=c/2a). So, we suggest that the anion position parameter χ in pure CuGaS2 crystal is close to the above value obtained by use of Ni+ ion probe. The optical absorption bands and g factors g∥, g⊥, of CuGaS2: Ni+ are therefore explained reasonably from the anion position parameter.