Analysis of electronic structure and quadrupole coupling in dimeric transition and nontransition halides in terms of the density functional theory

The electronic structure of dimeric M₂X₆ (M = Al, Ga, In, I; X = F, Cl, Br, I) and M₂X₁₀ (M = Sb, Nb; X = Cl, Br, I) was analyzed using the density functional theory. The calculated parameters of the nuclear quadrupole resonance spectra were compared with the experimental values. Binding of the bridging and terminal halogen atoms was examined using the natural orbitals of the metal-halogen bond. The inversion of the halogen NQR frequencies for the compounds of transition and nontransition elements is explained.