Electronic structure of X₂ Y₃ molecules (X = B, Al, Ga; Y = O,S): a theoretical study

Abstract

Ab initio molecular orbital and density functional theory calculations on X₂Y₃ (X = B, Al,Ga; Y = O,S) indicate a bent structure with C_2v symmetry to be the preferred arrangement for B₂ O₃, B₂ S₃ and Al₂S₃. In contrast, the linear isomer is favoured for Al₂ O₃ and Ga₂ O₃. These are in agreement with the experimentally observed structures. The electronegativity difference between X and Y, the MO patterns and the ionic nature of the bonding explain variations in the molecular structure. The results from the two theoretical approaches (MP2/6-31G^∗ and Becke3LYP/6-311 +G^∗ level) are comparable.