Browsing by Author "Zhu, Z. H."

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A QUASICLASSICAL TRAJECTORY STUDY OF REACTIVE SCATTERING ON AN ANALYTICAL POTENTIAL ENERGY SURFACE FOR GeH(2) SYSTEM
(2011-04-01)
Zhang, Li
;
Zhu, Chao-Yong
;
Jiang, Gang
;
Zhu, Chaoyuan
;
Zhu, Z. H.
A quasiclassical trajectory method was employed to study reaction Ge + H(2) (v = 0, j = 0) and reverse reaction H + GeH (v = 0, j = 0) on an analytical potential energy surface obtained from simplified many-body expansion method with fitting to B3P86/CC-pVTZ calculations around a global minimum and a long-range van de Waals well plus spectroscopy data for diatomic molecules GeH and H(2). Reaction probabilities from both reaction and reverse reaction were calculated. Dominant reaction is complex-forming reaction Ge + H(2) (v = 0, j = 0) -> GeH(2), and its cross section is 10 times bigger than that of complex-forming reaction from the reverse reaction. There is no threshold effect for complex-forming reaction and the cross sections for both complex-forming reactions decrease with the increase of collision energy. Life time of complex is shown to be decreasing with increase of collision energy. Dominant reverse reaction is reaction H + GeH (v = 0, j = 0) -> Ge + H(2); the reaction probability decreases with the increase of collision energy and differential cross section shows that this reverse reaction has almost equal angular distribution at low collision energy and mostly forward scattering at high collision energy.
A QUASICLASSICAL TRAJECTORY STUDY OF REACTIVE SCATTERING ON AN ANALYTICAL POTENTIAL ENERGY SURFACE FOR GeH2 SYSTEM
(2011-04-01)
Zhang, Li
;
Zhu, Chao-Yong
;
Jiang, Gang
;
Zhu, Chaoyuan
;
Zhu, Z. H.
A quasiclassical trajectory method was employed to study reaction Ge + H-2 (v = 0, j = 0) and reverse reaction H + GeH (v = 0, j = 0) on an analytical potential energy surface obtained from simplified many-body expansion method with fitting to B3P86/CC-pVTZ calculations around a global minimum and a long-range van de Waals well plus spectroscopy data for diatomic molecules GeH and H-2. Reaction probabilities from both reaction and reverse reaction were calculated. Dominant reaction is complex-forming reaction Ge + H-2 (v = 0, j = 0) -> GeH2, and its cross section is 10 times bigger than that of complex-forming reaction from the reverse reaction. There is no threshold effect for complex-forming reaction and the cross sections for both complex-forming reactions decrease with the increase of collision energy. Life time of complex is shown to be decreasing with increase of collision energy. Dominant reverse reaction is reaction H + GeH (v = 0, j = 0) -> Ge + H-2; the reaction probability decreases with the increase of collision energy and differential cross section shows that this reverse reaction has almost equal angular distribution at low collision energy and mostly forward scattering at high collision energy.
Thermodynamical study of the thermoelectric effect for magnesium silicide
(2007-09-27)
Zhu, Z. H.
;
Zhu, Chaoyuan
;
應用化學系分子科學碩博班
;
Institute of Molecular science
The thermoelectric effect of magnesium silicide is studied by using it thermodynamical method in the presence of an electric field. The thermoelectric potential is evaluated from the partial derivative of free energy with respect to charge in which the free energy is calculated at the B3LYP/6-31G(d,p) level of density functional theory. This free energy is also utilized to determine the average dipole moment from which the polarizability, alpha; molar polarization, Psi; and dielectric constant can be computed. The present calculation for the dielectric constant (similar to 24-20) is in very good agreement with the experimental value (20). This accurate dielectric constant can be used to derive the relation of the thermoelectric potential with respect to temperature, from which the thermoelectric power or the Seebeck coefficients are calculated. The present result shows good agreement with experiment measurement for the Seebeck coefficients. In comparison, that calculation from the energy band structure theory is far off from the experimental values.