Theoretical investigation of Wulf and Chappuis bands in the spectrum of ozone

The ground state and some lowest excited states of ozone are calculated by the semiempirical MNDO method using configuration interaction to explain the Wulf absorption band and photodissociation of ozone. The results of calculations show that3A2(13A′’) is the lowest excited triplet state of O3; a transition to this state from the ground X1 A1 state is responsible for the weak Wulf absorption. The oscillator strength (f = 3.2·10-7) and the radiative lifetime of the A2 state (Τ = 0.01 s) are in agreement with recent ab initio calculations.