Theoretical investigations of the optical spectra and g-shift in CsVX3 (X=ClX=Cl, Br, I)

The paper presents a molecular orbital calculation of the optical spectra and g shift in CsVX3 (X=ClX=Cl, Br, I), in which the contribution due to the electrostatic parameter A0A0, the Trees correction, the spin–orbit coupling of the central transition metal ion and the ligand are included. In the present calculations, instead of the 10 parameters in the previous works, there are three fitting parameters because the appropriate double-ζζ function of V2+V2+ is used. The calculated optical spectra and g shift agree well with the available experimental data. This indicates again that the double-ζζ wave functions are the appropriate approximation in the calculation of the electronic structure properties. The results show that the contribution due to the 3s of the ligand and the conjunct action between the center metal ion and the ligand cannot been neglected.