The partial potential energy surface of the I ＋ HI →IH ＋ I reaction involving the translational and vibrational motions has been constructed at the QCISD（ T ）//MP4SDQ level with the pseudo potential method that i...The partial potential energy surface of the I ＋ HI →IH ＋ I reaction involving the translational and vibrational motions has been constructed at the QCISD（ T ）//MP4SDQ level with the pseudo potential method that is helpful to interpreting the scattering resonance states. The lifetimes of the scattering resonance states in the title reaction obtained from the partial potential energy surface are about 90-120 fs, which agrees with the result of high-resolved threshold photodetachment spectroscopy of anion IHI^- measured by Neumark.展开更多
The partial potential energy surface was constructed by ab initio method [QCISD（T）/6- 311＋＋G（2df,2pd）]for F＋CH4→HF＋CH3 reaction system. It not only explained the reaction mechanism brought forward by Diego Tr...The partial potential energy surface was constructed by ab initio method [QCISD（T）/6- 311＋＋G（2df,2pd）]for F＋CH4→HF＋CH3 reaction system. It not only explained the reaction mechanism brought forward by Diego Troya by means of quasiclassical trajectory （QCT） but also successfully validated Kopin Liu＇s experimental phenomena about the existence of the reactive resonance. The lifetime of the scattering resonance state was about 0.07 ps. All these were in agreement with the experiments.展开更多
Reaction resonance or Feshbach resonance in polyatomic reaction is one of the most fascinating phenomena in chemical reaction dynamics. The HO+CH4→HO+CH3 reaction is one of the pivotal polyato-mic reactions concerned...Reaction resonance or Feshbach resonance in polyatomic reaction is one of the most fascinating phenomena in chemical reaction dynamics. The HO+CH4→HO+CH3 reaction is one of the pivotal polyato-mic reactions concerned with both the experimental and theoretical scientists. Reaction probabilities and other dynamic properties of this system were calculated with quantum scattering theory method, but a simple QH(v)+HO(j)→Q+H2O(m,n) reaction model was used, in which only three degrees of freedom and the rotating of OH were considered while making CH3 as a pseudo atom. In this paper, by an ab initio method, partial potential energy surface(PPES) was constructed and all the 15 internal degrees-freedom were given. Feshbach resonance mechanism of this reaction can be obtained by the dynamic Eyring Lake on the PPES and the lifetime of the reactive resonance-state can be estimated using the gap of the vibrational energy levels of transient collision complex in the critical transition-state region. Above interesting dynamic properties would not be given by simple pseudo atomic reaction model.展开更多
Cl+CH_(3)OH→HCl+CH_(3)O/CH_(2)OH is a prototypical multiple-channel reaction.Experimentally,ample dynamical and kinetic information is available,but there are still many uncertainties concerning the reaction mechanis...Cl+CH_(3)OH→HCl+CH_(3)O/CH_(2)OH is a prototypical multiple-channel reaction.Experimentally,ample dynamical and kinetic information is available,but there are still many uncertainties concerning the reaction mechanism.Theoretical investigations are rare due to the absence of a potential energy surface(PES),which has greatly hindered our understanding of the reaction dynamics.Using a machine-learning approach,an accurate full-dimensional PES for the title reaction based on tens of thousands of high-level ab initio data is reported.Comprehensive dynamical calculations were performed on the PES using quasi-classical trajectories,and the results provide insights into the reaction kinetics and dynamics.The calculated non-Arrhenius rate coefficients are consistent with the experimental data,attributable to a complex-forming mechanism at low temperatures.At high energies,the reaction is dominated by a direct mechanism,which results in dominant forward scattering via a stripping mechanism augmented by less prominent sideways and backward scattering via a rebound mechanism.At collision energies of 5.6 and 8.7 kcal/mol,the measured product translational energy and ro-vibrational state distributions of HCl are well reproduced.In addition,mode specificity is revealed and rationalized by the sudden vector projection model.This work sheds valuable light on the microscopic mechanism and dynamics of this prototypical multichannel reaction.展开更多
基金Supported by the National Natural Science Foundation of China(No. 20173032) Ph. D. Special Research Foundation ofMinistry of Education of China(No. 20020422027).
文摘The partial potential energy surface of the I ＋ HI →IH ＋ I reaction involving the translational and vibrational motions has been constructed at the QCISD（ T ）//MP4SDQ level with the pseudo potential method that is helpful to interpreting the scattering resonance states. The lifetimes of the scattering resonance states in the title reaction obtained from the partial potential energy surface are about 90-120 fs, which agrees with the result of high-resolved threshold photodetachment spectroscopy of anion IHI^- measured by Neumark.
基金the support of the Grant from the National Natural Science Foundation of China No.20573064 Ph.D.Special Research Foundation of Chinese Education Department.
文摘The partial potential energy surface was constructed by ab initio method [QCISD（T）/6- 311＋＋G（2df,2pd）]for F＋CH4→HF＋CH3 reaction system. It not only explained the reaction mechanism brought forward by Diego Troya by means of quasiclassical trajectory （QCT） but also successfully validated Kopin Liu＇s experimental phenomena about the existence of the reactive resonance. The lifetime of the scattering resonance state was about 0.07 ps. All these were in agreement with the experiments.
文摘Reaction resonance or Feshbach resonance in polyatomic reaction is one of the most fascinating phenomena in chemical reaction dynamics. The HO+CH4→HO+CH3 reaction is one of the pivotal polyato-mic reactions concerned with both the experimental and theoretical scientists. Reaction probabilities and other dynamic properties of this system were calculated with quantum scattering theory method, but a simple QH(v)+HO(j)→Q+H2O(m,n) reaction model was used, in which only three degrees of freedom and the rotating of OH were considered while making CH3 as a pseudo atom. In this paper, by an ab initio method, partial potential energy surface(PPES) was constructed and all the 15 internal degrees-freedom were given. Feshbach resonance mechanism of this reaction can be obtained by the dynamic Eyring Lake on the PPES and the lifetime of the reactive resonance-state can be estimated using the gap of the vibrational energy levels of transient collision complex in the critical transition-state region. Above interesting dynamic properties would not be given by simple pseudo atomic reaction model.
基金supported by the National Natural Science Foundation of China(No.21973009)Chongqing Municipal Natural Science Foundation(No.cstc2019jcyj-msxm X0087)。
基金supported by the National Natural Science Foundation of China(No.21773251 and No.21973098)the Youth Innovation Promotion Association CAS(No.2018045)the Beijing National Laboratory for Molecular Sciences。
基金supported by the National Natural Science Foundation of China(No.91641116,No.21433004,No.91753103,and No.21933010)the NYU Global Seed Grantthe Laboratory and Equipment Management Office of ECNU。
基金supported by National Natural Science Foundation of China(grant nos.21973009 and 21573027 to J.L.)US Department of Energy(grant no.DE-SC0015997 to H.G.)Chongqing Municipal Natural Science Foundation(grant no.cstc2019jcyjmsxmX0087 to J.L.)。
文摘Cl+CH_(3)OH→HCl+CH_(3)O/CH_(2)OH is a prototypical multiple-channel reaction.Experimentally,ample dynamical and kinetic information is available,but there are still many uncertainties concerning the reaction mechanism.Theoretical investigations are rare due to the absence of a potential energy surface(PES),which has greatly hindered our understanding of the reaction dynamics.Using a machine-learning approach,an accurate full-dimensional PES for the title reaction based on tens of thousands of high-level ab initio data is reported.Comprehensive dynamical calculations were performed on the PES using quasi-classical trajectories,and the results provide insights into the reaction kinetics and dynamics.The calculated non-Arrhenius rate coefficients are consistent with the experimental data,attributable to a complex-forming mechanism at low temperatures.At high energies,the reaction is dominated by a direct mechanism,which results in dominant forward scattering via a stripping mechanism augmented by less prominent sideways and backward scattering via a rebound mechanism.At collision energies of 5.6 and 8.7 kcal/mol,the measured product translational energy and ro-vibrational state distributions of HCl are well reproduced.In addition,mode specificity is revealed and rationalized by the sudden vector projection model.This work sheds valuable light on the microscopic mechanism and dynamics of this prototypical multichannel reaction.
