[01] A. Abdel-Hafiez, Department of Experimental Nuclear Physics, Nuclear Research Center, Atomic Energy Authority, Cairo, Egypt.

I have theoretically studied the nonadiabatic transitions among the lower states with =1u symmetry (1u(1) to 1u(3)) in the photodissociation of Br2 using the Comlete Active Space Self-Consistent Field (CASSCF) computations and the time-independent SchrÖdinger equations. The CASSCF wave function is formed from a complete distribution of a number of active electrons in a set of active orbitals, which in general constitute a subset of the total occupied space. From the configuration analysis of the CASSCF wavefunctions, we found that the nonadiabatic transition between 1u(2) and 1u(1) is a noncrossing type, while that between 1u(2) and B30+u is a crossing type. The spectroscopic constants for the X1g+, A31u and B30+u states of Br2 is calculated. The absorption cross-section for the ground and the lower excited states in the photodissociation of Br2 molecule is presented as well as the numerical estimates of nonadiabatic transition probabilities. Also, the five highest occupied and the five lowest unoccupied orbitals of Br2 have been calculated.

Algebraic technique / Quantum dynamics/ Electronic structure

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