Theoretical study of photodetachment processes of anionic boron cluster. III. B^-₇

Abstract

Photodetachment spectroscopy of B^-₇ is theoretically studied in this paper. Calculated photodetachment bands are compared with the available experimental results and assigned to the vibronic structure of the electronic ground and excited states of the neutral B7 cluster. The complex structure of photodetachment bands is found to arise from many stable isomers of B^-₇ of different symmetry point group. In this study we focus on three most stable isomers of B^-₇ and examine their photodetachment bands. Extensive quantum chemistry calculations are carried out to establish the potential energy surfaces and the coupling surfaces of the electronic states of neutral B₇ originating from each of the three isomers. A diabatic electronic ansatz is employed and the nuclear dynamics is studied both by time-independent and time-dependent quantum mechanical methods. Both agreements and discrepancies of the theoretical results with the experimental findings are discussed.