Jahn-Teller effect study of structural deformetion of OF2,OCl2 , OBr2, OI2

The structural properties of OF2, OCl2, OBr2,OI2 have been examined by means of B3LYP/Def2-TZVPP and LC-wPBE/ Def2-TZVPP and CCSD(T)/ Def2-TZVPP level theory interpretations. The results obtained showed the expected ground state structure for compound is linear.(D∞h symmetry) .The distortion of the high-symmetry configuration of compound is due to the pseudo Jahn-Teller effect(PJTE), which is the only source of instability of high-symmetry configuration in nondegenerate states.The distortion is due to the mixing of the ground and excited ∏u states [1].