| This thesis presents a recently developed physical model, Semirigid Vibrating Rotor Target (SVRT) model, for quantum dynamics study of general polyatomic reaction systems and its application to atom-polyatom and diatom-polyatom reaction. The SVRT model provides a general and realistic framework to describe stereo dynamics of ployatomic reaction correctly, and to contain the computational cost by significantly reducing the number of mathematical dimension of polyatomic reaction system.; The application of the SVRT model to the atom-polyatom reaction H + HOD → H2 + OD, HD + OH demonstrates the feasibility of SVRT model. In this application, the SVRT reaction probabilities and cross sections for both branching products are calculated. The excellent agreement of the SVRT results with that from early full dimensional dynamics calculation shows that this model is capable of giving quantitatively accurate dynamics information for polyatomic reaction.; The 6D SVRT dynamics study for diatom-polyatom chemical reaction is presented with the first initial state-selected reaction probabilities, cross sections and thermal rate constants for the benchmark reaction H 2 + CH3 → H + CH 4. The effects of the initial rotation and vibration of reagents on this reaction are examined in detail. In our study, the reagent CH 3 is treated as a three dimensional rigid rotor, and its spatial orientation motion is determined by three quantum numbers. The strong correlation between the reactivity and these quantum numbers shows the importance of the orientation motion in polyatomic reaction. |
