Infrared absorption in doped rare gas crystals

1983 ◽  
Vol 61 (11) ◽  
pp. 1545-1548 ◽  
Author(s):  
J. Vermesse ◽  
Dominique Levesque ◽  
Jean-Jacques Weis ◽  
Michael L. Klein

Molecular dynamics calculations based upon realistic pair potentials plus three body forces are used to investigate the properties of solid argon doped wth 2% krypton. The infrared absorption, which is computed using an expression for the interaction dipole moment derived from gas phase data, agrees well with experimental data.

1982 ◽  
Vol 60 (9) ◽  
pp. 1365-1370 ◽  
Author(s):  
Shūichi Nosé ◽  
Michael L. Klein

Molecular dynamics calculations employing atom–atom (exp-6) potentials are reported for solid argon in which 5% of the lattice sites are occupied by diatomic molecules. At temperatures close to the melting point (T ~ 80 K) the molecules are reorienting rapidly with no preferred orientation. Upon cooling, however, a distinct preference is observed for the crystallographic [Formula: see text] direction. Power spectra that characterize the translational and reorientational motions in the system have been evaluated. The results are discussed in light of available experimental data.


2010 ◽  
Vol 297-301 ◽  
pp. 1400-1407
Author(s):  
Giovano de Oliveira Cardozo ◽  
José Pedro Rino

Equilibrium and non-equilibrium molecular dynamics calculations of thermal conductivity coefficient are presented for bulk systems of InSb, using an effective two- and three-body inter atomic potential which demonstrated to be very transferable. In the calculations, the obtained coefficients were comparable to the experimental data. In the case of equilibrium simulations a Green-Kubo approach was used and the thermal conductivity was calculated for five temperatures between 300 K and 900 K. For the non equilibrium, or direct method, which is based on the Fourier’s law, the thermal conductivity coefficient was determined at a mean temperature of 300K. In this case it was used a pair of reservoirs, placed at a distance L from each other, and with internal temperatures fixed in 250 K, for the cold reservoir, and 350 K for the hot one. In order to obtain an approach to an infinite system coefficient, four different values of L were used, and the data was extrapolated to L→∞.


1986 ◽  
Vol 51 (6) ◽  
pp. 1222-1239 ◽  
Author(s):  
Pavel Moravec ◽  
Vladimír Staněk

Expression have been derived in the paper for all four possible transfer functions between the inlet and the outlet gas and liquid steams under the counter-current absorption of a poorly soluble gas in a packed bed column. The transfer functions have been derived for the axially dispersed model with stagnant zone in the liquid phase and the axially dispersed model for the gas phase with interfacial transport of a gaseous component (PDE - AD). calculations with practical values of parameters suggest that only two of these transfer functions are applicable for experimental data evaluation.


1991 ◽  
Vol 56 (10) ◽  
pp. 2020-2029
Author(s):  
Jindřich Leitner ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma ◽  
Rudolf Hladina

The authors proposed and treated quantitatively a kinetic model for deposition of epitaxial GaAs layers prepared by reaction of trimethylgallium with arsine in hydrogen atmosphere. The transport of gallium to the surface of the substrate is considered as the controlling process. The influence of the rate of chemical reactions in the gas phase and on the substrate surface on the kinetics of the deposition process is neglected. The calculated dependence of the growth rate of the layers on the conditions of the deposition is in a good agreement with experimental data in the temperature range from 600 to 800°C.


1989 ◽  
Vol 54 (11) ◽  
pp. 2933-2950
Author(s):  
Emerich Erdös ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma

This paper represents a continuation and ending of the kinetic study of the gallium arsenide formation, where a so-called inhomogeneous model is proposed and quantitatively formulated in five variants, in which two kinds of active centres appear. This model is compared both with the experimental data and with the previous sequence of homogeneous models.


2007 ◽  
Vol 72 (8) ◽  
pp. 1122-1138 ◽  
Author(s):  
Milan Uhlár ◽  
Ivan Černušák

The complex NO+·H2S, which is assumed to be an intermediate in acid rain formation, exhibits thermodynamic stability of ∆Hº300 = -76 kJ mol-1, or ∆Gº300 = -47 kJ mol-1. Its further transformation via H-transfer is associated with rather high barriers. One of the conceivable routes to lower the energy of the transition state is the action of additional solvent molecule(s) that can mediate proton transfer. We have studied several NO+·H2S structures with one or two additional water molecule(s) and have found stable structures (local minima), intermediates and saddle points for the three-body NO+·H2S·H2O and four-body NO+·H2S·(H2O)2 clusters. The hydrogen bonds network in the four-body cluster plays a crucial role in its conversion to thionitrous acid.


1970 ◽  
Vol 52 (4) ◽  
pp. 1782-1784 ◽  
Author(s):  
W. G. Hoover ◽  
A. C. Holt ◽  
D. R. Shortle ◽  
S. G. Gray

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