標題: Mechanism for singular behavior in vibrational spectra of topologically disordered systems: Short-range attractions
作者: Wu, TM
Chang, SL
Tsai, KH
物理研究所
Institute of Physics
公開日期: 22-五月-2005
摘要: At low-enough fluid densities, we have found some naive singular behavior, like the van Hove singularities in the phonon spectra of lattices, appearing in the instantaneous normal mode spectra of the Lennard-Jones (LJ) 2n-n fluids, which serve as a prototype of topologically disordered systems. The singular behavior cannot be predicted by the mean-field theory, but interpreted by the perturbed binary modes of some special pairs, called the mutual nearest neighbor pairs, at separations corresponding to the extreme binary frequencies, which are solely determined by the attractive part of the LJ 2n-n pair potential. By reducing the range of attraction in the pair potential under the conditions of the same particle diameter and well depth, the tendency for the appearance of the singular behavior shifts to higher fluid densities. From this study, we conclude that pair potential with a short-range attraction can be a mechanism to produce a counterpart of the van Hove singularity in the vibrational spectra of disordered systems without a reference lattice. 2005 American Institute of Physics.
URI: http://dx.doi.org/10.1063/1.1900726
http://hdl.handle.net/11536/13700
ISSN: 0021-9606
DOI: 10.1063/1.1900726
期刊: JOURNAL OF CHEMICAL PHYSICS
Volume: 122
Issue: 20
結束頁: 
顯示於類別:期刊論文


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