FIG. 9.

Experimental (black) and simulated (red) UV absorption spectra of [Fe(III)(C₂O₄)₃]³⁻ in water. The experimental spectrum is available only down to 210 nm. On the right, the dominant natural transition orbitals characterizing the electronic excitation for 15th excited state are shown. The electronic transition predominantly occurs from an occupied ligand orbital to an unoccupied metal atom orbital. Similar natural transition orbitals are observed for other transitions contributing to the same absorption band.