Experimental and theoretical studies of excited states of H2 observed in the absorption spectrum: II. The 6pπ and 7pπ1Πu states

Abstract

A comprehensive study of the absorption transitions leading to the 6pπ and 7pπ Rydberg states of H2 is presented which includes rovibronic level energies, line intensities and widths up to the 5th dissociation threshold of H2. The analysis of the experimental data is carried out with the help of multichannel quantum defect theory implemented here purely from first principles. The theory accounts for the strong rovibronic interactions which tie the 6pπ and 7pπ levels to the surrounding p Rydberg levels and continua, leading to strong perturbations of the level structure and decay mechanisms, and causing the appearance of numerous ‘complex’ resonance features.