A network of elimination reactions of H3PO in its ground state is examined by using ab initio (3-21G* and 6-31G** with MP3 perturbation corrections) wave functions. In addition to the eliminations, several isomerizations and internal rotations of the parent compound and its fragments are investigated. The insertion and reactive scattering reactions of H2 + HPO, which are characterized more fully with MP4(SDTQ) perturbation corrections, are followed by using the intrinsic reaction coordinate and energy-localized orbitals.