Experimental And Theoretical Studies On The Electronic States Of Some IIIA Monohalogen Molecules

The IIIA group monohalides play important roles in the development of new semiconductor and opto-electronic devices and the search for laser media. But until now, there are many problems in the spectra of IIIA group monohalides, for example, some experimentally found bands have not been assigned experimentally, some spectral results are dubious, and some spectra cannot be distinguished clearly being restricted by the experimental techniques. Moreover, the theoretical works have focused mainly on their ground states and the studies on their excited states are not abundant now. Therefore the electronic state structures of this group of molecules are not known very clearly. In this paper, the spectra of IIIA group monohalides are studied experimentally and theoretically. The following are the main contents. 1. The C 1Π→Χ1Σ+ transition of InBr molecule has been observed by laser-induced fluorescence, and the reliable spectroscopic constants of the C 1Πstate are obtained for the first time. 2. By using several quantum chemical methods (TDDFT, CCSD-LRT, MCQDPT, MR-CISD, MR-CISD+Q, MR-AQCC, et. al.), the electronic excited states of BBr, InCl, InBr, and InI, including Rydberg states, are studied theoretically for the first time. The spectroscopic constants are fitted, and the transition properties are also predicted. With the aid of the theoretical results, some problems existing in prevenient experimental results are solved. Moreover, the electronic states of InH are computed as well, and the obtained theoretical results are much better than old ones.