CORRELATIONS AND LEVEL STATISTICS IN COMPLEX SPECTRA

The relativistic configuration interaction method has been used for th e investigation of the Sri spectrum which arises from excitation of on e electron out of the 4p shell. Many-body effects are found to dominat e the lower part of this spectrum through extensive configuration mixi ng. Oscillator strengths for the transitions between these levels and the Sri found state are used to obtain a convoluted Sri absorption spe ctrum. Theoretical predictions for the structure and position of Sr II levels, serving as Sr I series limits in corresponding experimental i nvestigations, are also provided. A statistical analysis was carried o ut on the theoretically predicted Sri level energies and a Wigner dist ribution for them has been obtained. This is a consequence of the stro ng configuration mixing, which in turn is related to the contraction o f the Sr 4d orbital. A value of 0.59 for the Brody parameter q, a meas ure of deviations from equal interlevel spacings and an indicator of t he degree of level repulsion, has been determined.