Direct Photodissociation and Spontaneous Radiative Dissociation of H₂

As the most abundant molecule in the universe, molecular hydrogen (H₂) plays a significant role in the evolutionary mechanisms of astrophysical environments. This study systematically investigates the direct photodissociation process of H₂ from the ground state to the excited B and C states, taking into account the effects of temperature. The direct photodissociation cross sections at various temperatures are calculated, and the corresponding dissociation rates in a blackbody radiation field are evaluated accordingly. Additionally, the spontaneous radiative dissociation rates resulting from transitions from excited states to the continuum regions of lower electronic states, as well as the lifetimes of excited states, are discussed. All calculations are based on the latest high-precision molecular potential energy curves and transition dipole moments. The results obtained provide high-accuracy reference data for studies on the dissociation dynamics of molecular hydrogen and related models.