Unified quantum-defect-theory treatment of molecular ionization and dissociation

Multichannel quantum-defect theory is extended to treat molecular dissociation processes simultaneously with ionization processes. Allowance is made for nuclear momentum coupling and for coupling with core excited channels. This theory combines the advantages of several less comprehensive approaches and is noniterative, nonperturbative, and applicable for arbitrary interaction strength. Several examples showing good agreement with experimental results relating to the ${\mathrm{H}}_2$ molecule are given.