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
An analytic expression of the potential energy surface(PES) of the ground state of the Ne-HF complex is obtained by utilizing nonlinear least square method to fit the intermolecular interaction energies [Zhang Y. Guiz...An analytic expression of the potential energy surface(PES) of the ground state of the Ne-HF complex is obtained by utilizing nonlinear least square method to fit the intermolecular interaction energies [Zhang Y. Guizhou Science,2003,21(3):9-13(in Chinese)],which have been computed using the augmented correlation-consistent polarized quadruple zeta basis set aug-cc-pVQZ at the theoretical level of CCSD(T). On the basis of the PES,the partial cross sections(PCSs) at the incident energies of 60,75,100 and 150 meV for collisions between Ne atoms and HF molecules are calculated using the quantum close coupling approach. The effects of the long-range attractive and the short-range anisotropic interactions on the inelastic PCSs are discussed in detail. The results show:(1) The long-range attractive well of the EPS makes the significant contribution to the lower excitation PCSs,especially the tail maximum for j = 0→j′ = 1 transitions,whereas no contribution is to the j′≥3 inelastic transitions.(2) The short-range(the repulsive and attractive) interaction makes the significant contri-bution to the lower excitation PCSs,especially the main peak for j = 0→j′ = 1,2. As for the transitions of j′≥3,the short-range interaction plays a key role in the inelastic excitation.(3) Although the positions of the maximums and minimums of the inelastic PCSs are different at the collision energies,they correspond to almost the same impact parameter.展开更多
An interaction potential of the Ne-HC1 van der Waals complex is obtained by utilizing the Huxley analytic potential function to fit the accurate interaction energy data, which have been computed at the coupled cluster...An interaction potential of the Ne-HC1 van der Waals complex is obtained by utilizing the Huxley analytic potential function to fit the accurate interaction energy data, which have been computed at the coupled cluster singles and doubles including connected triple excitations level and with the augmented correlation consistent polarized valence quintuple zeta basis set extended with a set of 3s3p2dlflg mid-bond functions [CCSD （T）/aug-cc-pV5Z-33211]. The close coupling calculation of state-to-state partial cross sections for collision of Ne with HC1 is first performed by employing the fitted interaction potential. This calculation is performed at the incident energies： 40, 60, 75 and 100 meV, separately. The effects of the long-range attractive and the short-range anisotropic interactions on the inelastic state-to-state partial cross sections are discussed in detail. Two maxima are present in the rotationally inelastic partial cross sections and they originate from different mechanisms.展开更多
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（PPES） of Br＋HBr（v=0）→BrH（v＇=0）＋Br was designed by coupling the vibration energy and the minimum energy of the corresponding reaction path, Vmep. All the calculations were...The partial potential energy surface（PPES） of Br＋HBr（v=0）→BrH（v＇=0）＋Br was designed by coupling the vibration energy and the minimum energy of the corresponding reaction path, Vmep. All the calculations were performed at the theoritical level of QCISD（T）/6-311＋＋G＊＊//MP2/6-31 1＋＋G＊＊. Based on the analysis of PPES, the dynamic ＂Eyring Lake＂ mechanism gave birth to the scattering resonance state. The resonance energy was also obtained via PPES. Then a lifetime matrix of the resonance state was established by solving the translational wave-function via the numerical propagation method. Then the reaction resonance lifetime was calculated to be 125 fs. It is in good agreement with the experimental result.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
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 (Grant Nos. 10676025 and 10574096)
文摘An analytic expression of the potential energy surface(PES) of the ground state of the Ne-HF complex is obtained by utilizing nonlinear least square method to fit the intermolecular interaction energies [Zhang Y. Guizhou Science,2003,21(3):9-13(in Chinese)],which have been computed using the augmented correlation-consistent polarized quadruple zeta basis set aug-cc-pVQZ at the theoretical level of CCSD(T). On the basis of the PES,the partial cross sections(PCSs) at the incident energies of 60,75,100 and 150 meV for collisions between Ne atoms and HF molecules are calculated using the quantum close coupling approach. The effects of the long-range attractive and the short-range anisotropic interactions on the inelastic PCSs are discussed in detail. The results show:(1) The long-range attractive well of the EPS makes the significant contribution to the lower excitation PCSs,especially the tail maximum for j = 0→j′ = 1 transitions,whereas no contribution is to the j′≥3 inelastic transitions.(2) The short-range(the repulsive and attractive) interaction makes the significant contri-bution to the lower excitation PCSs,especially the main peak for j = 0→j′ = 1,2. As for the transitions of j′≥3,the short-range interaction plays a key role in the inelastic excitation.(3) Although the positions of the maximums and minimums of the inelastic PCSs are different at the collision energies,they correspond to almost the same impact parameter.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10676025 and 10574096）, the Discipline Foundation of Anqing Teachers College of China （Grant No 044-k06016000007） and the Anhui Provincial Natural Science Foundation of China （Grant No 20050610010）.
文摘An interaction potential of the Ne-HC1 van der Waals complex is obtained by utilizing the Huxley analytic potential function to fit the accurate interaction energy data, which have been computed at the coupled cluster singles and doubles including connected triple excitations level and with the augmented correlation consistent polarized valence quintuple zeta basis set extended with a set of 3s3p2dlflg mid-bond functions [CCSD （T）/aug-cc-pV5Z-33211]. The close coupling calculation of state-to-state partial cross sections for collision of Ne with HC1 is first performed by employing the fitted interaction potential. This calculation is performed at the incident energies： 40, 60, 75 and 100 meV, separately. The effects of the long-range attractive and the short-range anisotropic interactions on the inelastic state-to-state partial cross sections are discussed in detail. Two maxima are present in the rotationally inelastic partial cross sections and they originate from different mechanisms.
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 National Natural Science Foundation of China
文摘The partial potential energy surface（PPES） of Br＋HBr（v=0）→BrH（v＇=0）＋Br was designed by coupling the vibration energy and the minimum energy of the corresponding reaction path, Vmep. All the calculations were performed at the theoritical level of QCISD（T）/6-311＋＋G＊＊//MP2/6-31 1＋＋G＊＊. Based on the analysis of PPES, the dynamic ＂Eyring Lake＂ mechanism gave birth to the scattering resonance state. The resonance energy was also obtained via PPES. Then a lifetime matrix of the resonance state was established by solving the translational wave-function via the numerical propagation method. Then the reaction resonance lifetime was calculated to be 125 fs. It is in good agreement with the experimental result.
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.
