Delocalized \pi_3^6 Bond in OX_2 (X=Halogen) Molecules

OX_2 (X=halogen) molecules was studied theoretically. Calculation results show that delocalized \pi_3^6 bonds exist in their electronic structures and O atoms adopt the sp^2 type of hybridization, which violates the prediction of the valence shell electron pair repulsion theory of sp^3 type. Delocalization stabilization energy is proposed to measure the contribution of delocalized \pi_3^6 bond to energy decrease and proves to bring extra-stability to the molecule. These phenomena can be summarized as a kind of coordinating effect.