Electronic structure of X_2 Y_3 molecules (X = B, Al, Ga; Y = O, S): A theoretical study

摘要

Ab initio molecular orbital and density functional theory calculations on X_2Y_3 (X = B,Al,Ga; Y = O,S) indicate a bent structure with C_(2v) symmetry to be the preferred arrangement for B_2 O_3, B_2 S_3 and A1_2 S_3. In contrast, the linear isomer isfavoured for A1_2O_3 and Ga_2O_3. 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.