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Ab Initio molecular dynamics study of ethylene adsorption onto Si(001) surface: Short‐time fourier transform analysis of structural coordinate autocorrelation function
Author(s) -
Lee Yung Ting,
Lin Jyh Shing
Publication year - 2013
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.23434
Subject(s) - adsorption , ethylene , molecular dynamics , chemistry , ab initio , molecular vibration , reaction coordinate , infrared , fourier transform infrared spectroscopy , reaction dynamics , autocorrelation , fourier transform , infrared spectroscopy , density functional theory , computational chemistry , crystallography , molecule , chemical engineering , physics , organic chemistry , statistics , mathematics , quantum mechanics , optics , engineering , catalysis
The reaction dynamics of ethylene adsorption onto the Si(001) surface have been studied by combining density functional theory‐based molecular dynamics simulations with molecular adsorption sampling scheme for investigating all kinds of reaction pathways and corresponding populations. Based on the calculated results, three possible reaction pathways—the indirect adsorption, the direct adsorption, and the repelling reaction—have been found. First, the indirect adsorption, in which the ethylene (C 2 H 4(ads) ) forms the π‐bonded C 2 H 4(ads) with the buckled‐down Si atom to adsorb on the Si(001) surface and then turns into the di‐σ‐bonded C 2 H 4(ads) , is the major reaction pathway. The short‐time Fourier transform analysis of structural coordinate autocorrelation function is performed to further investigate the evolution of different vibrational modes along this indirect reaction pathway. This analysis illustrates that the Infrared (IR) inactive peak of the CC stretching mode of the π‐bonded C 2 H 4(ads) shifts to the IR inactive peak of the CC stretching mode of di‐σ‐bonded C 2 H 4(ads) , which is in a good agreement with the IR inactive peak of the CC stretching mode vanished in the vibrational spectrum at 150 K (Nagao et al., J. Am. Chem. Soc . 2004 , 126 , 9922). Second, the direct adsorption, in which the di‐σ‐bonded C 2 H 4(ads) is formed directly with the Si intradimer or the Si interdimer on the Si(001) surface, is the less significant reaction pathway. This reaction pathway leads to the CC stretching mode and the CH stretching mode of the di‐σ‐bonded C 2 H 4(ads) appeared in the vibrational spectra at 48 and 150 K, respectively (Nagao et al., J. Am. Chem. Soc . 2004 , 126 , 9922). Finally, the repelling reaction, in which the C 2 H 4(g) first interacts with the Si dimer and then is repelled by Si atoms, is the least important reaction pathway. Consequently, neither the π‐bonded C 2 H 4(ads) nor the di‐σ‐bonded C 2 H 4(ads) is formed on the Si(001) surface. © 2013 Wiley Periodicals, Inc.