Shiliang Ding

Dynamical Lie algebraic approach to rotationally inelastic scattering of molecules from surfaces

Abstract This paper describes a dynamical Lie algebraic method that we have developed in the application of the theory of Alhassid and Levine [Phys. Rev. A 18 (1978) 89] to rotationally inelastic molecule–surface scattering. Transition probabilities and their dependence on main dynamics variables of the collision system can be given analytically. An application of the method to direct rotationally inelastic scattering of NO molecules from a static, flat Ag(111) surface is made. Calculations performed for this model system yield snapshots of the probability current density and those of the rate of change of probability density that provide an insight into the intimate details of the scattering dynamics in time. The results show that this method is efficient and more useful to the inelastic scattering problems.

Statistical mechanics of rotationally inelastic molecule–surface scattering in the dynamical Lie algebraic method

The dynamical Lie algebraic method is used for the description of statistical mechanics of rotationally inelastic molecule–surface scattering. A main advantage of this method is that it can not only give the expression for evolution operator in terms of the group parameters, but also provide the expression for the density operator for a given system. The group parameters may then be determined by solving a set of coupled nonlinear differential equations. Thus, the expressions of the statistical average values of the translational-to-rotational energy transfer, the interaction potential, and their dependence on the main dynamic variables for the system are derived in terms of the density operator formalism in statistical mechanics. The method is applied to the scattering of NO molecules from a static, flat Ag(111) surface to illustrate its general procedure. The results demonstrate that the dynamical Lie algebraic method can be useful for describing statistical dynamics of gas–surface scattering.

Algebraic approach to the potential energy surface for the electronic ground state of ozone

Abstract A potential energy surface for the electronic ground state of the O 3 molecule is obtained using U (4) group. This potential energy surface includes the information of bending motion. Additionally, some properties, for example, saddle points, are discussed.

Dynamical Lie algebraic approach to energy transfer of the scattering system A+BC

The dynamical Lie algebraic approach developed by Y. Alhassid and R.D. Levine combined with the intermediate picture is applied to the study of translational-vibrational energy transfer in the collinear collision between an atom and an anharmonic oscillator. By solving equations of motion for the group parameters under the first-order approximation of the group parameters, the authors calculate the vibrational transition probabilities of anharmonic molecule scattering with an atom in the intermediate picture. Numerical test calculations are carried out for the collinear scattering system HBr + He; the results show that the dynamical Lie algebraic approach can be useful for the description of atom-molecule collision phenomena.

Potential energy surface for linear triatomic molecules: An algebraic method

Recently, we proposed a new transformation between the angle of canonical coordinates and the bond angle to describe the bending motion in Potential Energy Surfaces (PES) of bent triatomic molecules. In this work we extend the transformation to include linear triatomic molecules. Results for the linear triatomic molecule N2O are reported.

An application of the dynamical Lie algebraic method to energy transfer of the collinear scattering system AB+CD

The dynamical Lie algebraic method has been applied to treat the V–V and T–V energy transfers in the collinear scattering system AB+CD. The expression for the vibrational transition probability, which contains the main dynamical parameters, is given analytically. By using this expression we probe into the V–V resonance and T–V resonance phenomena appearing in the process of energy transfer. We find that the transition probability of V–V resonance is in good agreement with that obtained using the resonant exchange hypothesis. Then the reliability of the resonant exchange hypothesis is confirmed.

Lie algebraic approach to multiphoton rovibrational transition of diatomic molecule in intense laser fields

Abstract The multiphoton rovibrational excitation of diatomic molecule in intense laser fields is studied by using simulated potential and Lie algebraic approach. The rovibrational transition probability as a function of external field frequency and time, respectively, for the molecules HF, NO and LiH is calculated. The influences of the rotation on the multiphoton processes are investigated.

The effects of the motion of the surface atom on resonant charge transfer in atom–surface scattering

Abstract A simplified version of a semiclassical common eikonal formalism for the description of resonant charge transfer occurring in atom–surface scattering has been extended to incorporate the effect of motion of the surface atom on the charge-transfer probability. Specifically, the dependence of the ionization probability on the initial kinetic energy is derived explicitly. The formalism is applied to the scattering of hyperthermal sodium atoms from the W(110) surface. The results show that the ionization probabilities display Stuckelberg oscillations as a function of initial kinetic energy. The effect of motion of the surface atom can be seen in the appreciable change in the magnitude and frequency of these oscillations of the ionization probabilities. The results also give an indication of the importance of energy transfer in determining the ionization probability of hyperthermal sodium atoms on the W(110) surface.

Dynamical Lie algebraic treatment for the A+BC scattering

We report the study of translational-vibrational energy transfer in the a + bc scattering using the dynamical lie algebraic approach combined with the intermediate picture. the rotational sudden approximation is applied to treat the rotational motion of the bc molecule, which is regarded as an anharmonic oscillator. the calculated results show that the transition probabilities increase with increasing rotational quantum number. comparison with those obtained in the collinear collision of system a + bc manifests that the transition probabilities here increase indeed. (c) 2001 john wiley sons, inc.

Study on multiphoton processes in intense laser fields using the quadratic anharmonic Lie algebraic hamiltonian of diatomic molecule

Abstract The quadratic anharmonic Lie algebraic hamiltonian of a non-rotation Mores oscillator is used to study the multiphoton processes of diatomic molecule placed in intense laser fields. The averaged absorb energy spectra of multiphoton transition are calculated. The long-time behaviors and the effect of laser phase in multiphoton process also are investigated.