The anharmonic effect study of coupled Morse oscillators for the unimolecular reaction  

作　　者：YAO Li1,2 & LIN Sheng-Hsien2,31 Department of Physics, Dalian Maritime University, Dalian 116026, China 2 Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10764, China 3 Department of Applied Chemistry and Institute of Molecular Sciences, Chiao-Tung University, Hsinchu 30051, Taiwan, China 

出　　处：《Science China Chemistry》2008年第12期1146-1152,共7页中国科学（化学英文版）

基　　金：Supported by the National Natural Science Foundation of China (Grant No. 10704012);NSC (Taiwan), Academia Sinica, and the Natural Science Foundation of Liaoning Province (Grant No. 2006Z064)

摘　　要：The importance of anharmonic effect in dissociation of molecular systems especially clusters has been noted. In this paper, we shall study the effect of coupled anharmonic oscillator of the standard bilinear form (SBF) Morse oscillator (MO) potential on unimolecular reaction. We shall use the systematic theoretical approach, YL method, proposed by Yao and Lin (YAO L, et. al. J Phys Chem A, 2007, 111(29): 6722-6729), which can evaluate anharmonic effects on the rate constants based on the transition state theory. In treating the anharmonic effect with the Morse oscillator potential on unimolecular reactions under collision-free conditions by using the RRKM (Rice-Ramsperger-Kassel-Marcus) theory, the in-verse Laplace transformation of the partition functions was used to obtain the total amount of state and density of state by using the first-order and the second-order approximations of the saddle-point method. To demonstrate the anharmonic effect of the SBF Morse model, we choose some model systems and a real reaction as examples.The importance of anharmonic effect in dissociation of molecular systems especially clusters has been noted. In this paper, we shall study the effect of coupled anharmonic oscillator of the standard bilinear form (SBF) Morse oscillator (MO) potential on unimolecular reaction. We shall use the systematic theoretical approach, YL method, proposed by Yao and Lin (YAO L, et. al. J Phys Chem A, 2007, 111(29): 6722–6729), which can evaluate anharmonic effects on the rate constants based on the transition state theory. In treating the anharmonic effect with the Morse oscillator potential on unimolecular reactions under collision-free conditions by using the RRKM (Rice-Ramsperger-Kassel-Marcus) theory, the inverse Laplace transformation of the partition functions was used to obtain the total amount of state and density of state by using the first-order and the second-order approximations of the saddle-point method. To demonstrate the anharmonic effect of the SBF Morse model, we choose some model systems and a real reaction as examples.

关 键 词：ANHARMONIC effect standard BILINEAR form MORSE OSCILLATOR rate CONSTANT RRKM theory 

分 类 号：O641.1[理学—物理化学]