Molecular-dynamics calculation of the vibrational densities of states and infrared absorption of crystalline rare-gas mixtures

1992 ◽  
Vol 46 (17) ◽  
pp. 10738-10742 ◽  
Author(s):  
S. Gonçalves ◽  
H. Bonadeo
Keyword(s):  
Molecular Dynamics ◽  
Infrared Absorption ◽  
Gas Mixtures ◽  
Rare Gas ◽  
Densities Of States ◽  
Dynamics Calculation

Studies in Molecular Dynamics by Collision-Induced Infrared Absorption in H2–Rare Gas Mixtures. II. Diffusional Narrowing of Quadrupole-Induced Transitions

1973 ◽  
Vol 51 (18) ◽  
pp. 1971-1977 ◽  
Author(s):  
J. W. Mactaggart ◽  
J. De Remigis ◽  
H. L. Welsh
Keyword(s):  
Molecular Dynamics ◽  
Infrared Absorption ◽  
Diffusion Coefficients ◽  
Reasonable Agreement ◽  
Liquid Mixtures ◽  
Gas Mixtures ◽  
Rare Gas ◽  
Density Region ◽  
Vapor Line ◽  
High Density Region

The profiles of the quadrupole-induced transitions (S1(0), S1(1)) of the pressure-induced fundamental infrared absorption band of hydrogen are studied in H2–Ar, H2–Kr, and H2–Xe gas mixtures up to high densities a few degrees above the critical temperature of the rare gas and in the corresponding liquid mixtures along the liquid–vapor line. The half-width δq of the transitions remains practically constant for the gas mixtures up to densities of several hundred amagat and then decreases rapidly. Values of δq for the liquid mixtures, when corrected for the temperature difference, are the same as the gas values at the same density. The narrowing of the transitions in the high-density region is interpreted in terms of the diffusional narrowing theory of Zaidi and Van Kranendonk, and is used to calculate diffusion coefficients D12 of H2 molecules in dense rare gas fluids. The results are in reasonable agreement with values of D12 previously deduced from the intercollisional interference effect in the overlap-induced components (Q1(0), Q1(1)) of the same band.

COLLISION-INDUCED ABSORPTION OF COMPRESSED GASES IN THE FAR INFRARED, PART I

1965 ◽  
Vol 43 (5) ◽  
pp. 729-750 ◽  
Author(s):  
D. R. Bosomworth ◽  
H. P. Gush
Keyword(s):  
Fourier Analysis ◽  
Infrared Absorption ◽  
Michelson Interferometer ◽  
Far Infrared ◽  
Gas Mixtures ◽  
Experimental Techniques ◽  
Rare Gas ◽  
Absorption Coefficients ◽  
Induced Absorption ◽  
Separate Paper

A study is being made of the far infrared absorption occurring in compressed rare-gas mixtures, and compressed homonuclear diatomic gases. The region investigated lies between 20 and 400 cm−1. The spectra are obtained from the Fourier analysis of interferograms produced by a dynamic Michelson interferometer. It is possible to obtain accurate absolute absorption coefficients for broad bands using this method provided care is exercised in the analysis of the interferograms. The necessary precautions are discussed in detail. The precision of the method obtained in practice is demonstrated using the far infrared bands of hydrogen and nitrogen as examples. Only the experimental techniques are discussed in this paper; the detailed results follow in a separate paper.

A Molecular Dynamics Investigation of C60 –Rare Gas Mixtures

1994 ◽  
Vol 359 ◽  
Author(s):  
Maria C. Abramo ◽  
C. Caccamo
Keyword(s):  
Molecular Dynamics ◽  
Gas Mixtures ◽  
Rare Gas ◽  
Classical Molecular Dynamics

ABSTRACTMixtures of krypton atoms and C60, modelled in terms of rigid spherical molecules, are investigated at T ≃ 1800K through classical Molecular Dynamics. The two species do not tend to mix for low to moderate concentrations of krypton, and solid clusters of C60 tend to be stable. Possible implications of these results are shortly discussed.

Induced far-infrared absorption in rare-gas mixtures

1976 ◽  
Vol 16 (6) ◽  
pp. 491-498 ◽  
Author(s):  
J. Quazza ◽  
Ph. Marteau ◽  
H. Vu ◽  
B. Vodar
Keyword(s):  
Infrared Absorption ◽  
Far Infrared ◽  
Gas Mixtures ◽  
Rare Gas

Studies in Molecular Dynamics by Collision Induced Infrared Absorption in H2–Rare Gas Mixtures. III. H2–He Mixtures at Low Temperatures and Densities

1975 ◽  
Vol 53 (19) ◽  
pp. 2060-2067 ◽  
Author(s):  
A. R. W. McKellar ◽  
J. W. Mactaggart ◽  
H. L. Welsh
Keyword(s):  
Molecular Dynamics ◽  
Low Temperature ◽  
Infrared Absorption ◽  
Interference Effect ◽  
Low Temperatures ◽  
Profile Analysis ◽  
Rare Gas ◽  
Absorption Profile ◽  
Higher Temperature ◽  
Density Results

The collision induced fundamental band of H2 has been studied in H2–He mixtures with absorption paths of 110 and 165 m in a low temperature multiple traversal cell. Spectra were obtained at 18 and 61.5 K with densities in the range of 9 to 60 amagat. Under these conditions the structure of the band is particularly simple and amenable to analysis; the results of a profile analysis of the present spectra are compared with the higher temperature and density results in paper I (Mactaggart and Welsh) of this series. The long observed splitting of the Q branch of the H2 fundamental is manifested here as very sharp dips in the absorption profile at the Q1(0) and Q1(1) molecular frequencies and these provide a striking confirmation of Van Kranendonk's explanation of the 'splitting' as due to an intercollisional interference effect.

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