The Analytical Potential Energy Surface And Dynamics Of C+H₂â†'CH+H

The methylene （CH₂） molecule is an important intermediate in many organic reactionsbecause it has unique spectroscopic and chemical characteristics. So the CH₂molecule playsan important role in combustion and astrochemical processes. Due to in several subfields ofchemistry, the CH₂molecule has been the subject of extensive spectroscopic investigation.In the fist place, the multi-reference configuration interaction method and big base setaug-cc-pV5Z were used to calculate the excited state of HH and CH, hereafter we buildpotential energy curves. Compared with the single reference configuration method, the MRCImetheod is more appropriated for Ab initio calculation of diatomic molecules, because it canconsider the correlation energy very comprehensively. Murrell Sorbie and Aguado Paniaguafunction were used to fit HH, CH, CH₂, respectively. Total16478energy points werecalculated. The new function is completely analyzed, so can be used to quickly calculate thedynamic nature in the new CH₂potential energy surface.Secondly, in order to show the complete dynamic properties, we studied the scalar andvector nature in the excited（1D） state potential energy surface based on the new CH₂potential energy surface. The reaction cross-sections for different collision energies from0.1to0.6eV and different rotational levels j=0,1at collision energies0.08eV have beencomputed and compared with Bussery-Honvault and Banares’s theoretical data. The resultsare better than that the theoretical data. For the purpose of comparing the nature of the CH₂potential energy surface more broadly with other groups and to test the quality of the newpotential energy surface, we also studied the stereodynamics for the reaction when it wascalculated at different collision energies0.1,0.3and0.5eV using the quasi-classical trajectorymethod, and then we study the effect of vibrational excitation for the CH₂, at last, wediscussed the isotope effect on the system. All of this can deepen the understanding of theC+H2â†'CH+H system for us.