Molecular electronic structure of aluminium trihalide dimers and their quadrupole couplings by the SCF–MS molecular-orbital method

Abstract

SCF–multiple scattering calculations have been performed on the aluminium trihalide dimers (Al₂X₆, X = F, Cl, Br, I), and the nuclear quadrupole constants of ²⁷Al and the halides have been calculated except for the fluoride. The calculated quadrupole constants compare reasonably well with experiment except for Al₂Cl₆. The cause of the disagreement between the calculated and experimental quadrupole constants in Al₂Cl₆ is discussed. The calculated ionization potentials of Al₂Cl₆ agree with experiment better than those from an ab initio STO-2G calculation. The effect of the sphere sizes on the results has also been studied.