CCSD(T) potential energy and induced dipole surfaces for N2–H2(D2): Retrieval of the collision-induced absorption integrated intensities in the regions of the fundamental and first overtone vibrational transitions

2012 ◽  
Vol 137 (11) ◽  
pp. 114308 ◽  
Author(s):  
Ilya Buryak ◽  
Sergei Lokshtanov ◽  
Andrey Vigasin
Keyword(s):  
Potential Energy ◽  
Induced Absorption ◽  
Induced Dipole ◽  
Vibrational Transitions ◽  
Integrated Intensities

Far-infrared collision-induced absorption in compressed gaseous polar linear molecules: application to N2O

1988 ◽  
Vol 66 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Nguyen- Van-Thanh ◽  
I. Rossi
Keyword(s):  
Quadrupole Moment ◽  
Far Infrared ◽  
Pressure Data ◽  
Induced Absorption ◽  
A Value ◽  
Induced Dipole ◽  
Linear Molecules ◽  
Bimolecular Collisions ◽  
Integrated Intensities ◽  
Rotational Interaction

This paper deals with computations of the far-infrared collision-induced absorptions for polar linear molecules. We have considered Frost's theory for dipole- and quadrupole-induced dipole absorptions in bimolecular collisions, taking the anisotropy of the molecular polarizability into account. In addition to the induced rotational interaction, a translational effect may not be negligible. Detailed expressions for different contributions to the integrated intensities are reported for N2O. Using these calculated expressions and the moderately low pressure data, we have deduced a value for the quadrupole moment of N2O, [Formula: see text].

Lineshapes and dipole moments in collision-induced absorption

1981 ◽  
Vol 59 (10) ◽  
pp. 1544-1554 ◽  
Author(s):  
George Birnbaum ◽  
Michael S. Brown ◽  
Lothar Frommhold
Keyword(s):  
Dipole Moment ◽  
Dipole Moments ◽  
Empirical Models ◽  
Fundamental Theory ◽  
Potential Models ◽  
Induced Absorption ◽  
Induced Dipole ◽  
Substantial Error ◽  
Argon Mixture ◽  
Helium Neon

Wave mechanical lineshapes of collision-induced absorption spectra are computed for binary mixtures of argon with helium, neon, and krypton using theoretical dipole moments as input. Comparison with measured spectra shows satisfactory agreement except for the neon–argon mixture, for which either theory or measurement is seen to be in substantial error. Empirical models of the collision-induced dipole moment which reproduce the experimental spectra more closely than the fundamental theory are also given. Best agreement between computed and experimental lineshapes is obtained when potential models which are accurate in the repulsive region are used.

Spectral lineshapes of collision-induced absorption (CIA) using isotropic intermolecular potential for N2-CH4

2021 ◽  
Vol 21 (4) ◽  
pp. 1063-1078
Author(s):  
M.S.A. El-Kader ◽  
G. Maroulis ◽  
T. Bancewicz
Keyword(s):  
Potential Model ◽  
Dipole Moments ◽  
Molecular Nitrogen ◽  
Intermolecular Potential ◽  
Gaseous Mixtures ◽  
Induced Absorption ◽  
Induced Dipole ◽  
Different Temperatures ◽  
Experimental Absorption ◽  
Good Agreement

Quantum mechanical lineshapes of collision-induced absorption (CIA) at different temperatures are computed for gaseous mixtures of molecular nitrogen and methane using theoretical values for the induced dipole moments and intermolecular potential as input. Comparison with theoretical absorption spectra shows satisfactory agreement. An empirical model of the dipole moment which reproduces the experimental spectra and the first three spectral moments more closely than the fundamental theory, is also presented. Good agreement between computed and experimental absorption lineshapes is obtained when a potential model which is constructed from the thermophysical and transport properties is used.

Fitting potential energy and induced dipole surfaces of the van der Waals complex CH4-N2 using non-product quadrature grids

2021 ◽  
Author(s):  
Artem Finenko ◽  
Daniil N. Chistikov ◽  
Yulia N. Kalugina ◽  
Eamon K. Conway ◽  
Iouli Gordon
Keyword(s):  
Potential Energy ◽  
Ab Initio ◽  
Van Der Waals ◽  
Extensive Study ◽  
Rigid Rotor ◽  
Van Der Waals Complex ◽  
Induced Dipole

We present an extensive study of the five-dimensional potential energy and induced dipole surfaces of the CH4-N2 complex assuming rigid-rotor approximation. Within the supermolecular approach, ab initio calculations of the...

On nuclear spin statistics in rotational transition intensities in tetrahedral AB4 molecules

1979 ◽  
Vol 57 (8) ◽  
pp. 1081-1089 ◽  
Author(s):  
Arieh Rosenberg ◽  
Joel Susskind
Keyword(s):  
Dipole Moment ◽  
Nuclear Spin ◽  
Rotational Transition ◽  
Polarizability Tensor ◽  
Centrifugal Distortion ◽  
Induced Dipole ◽  
Integrated Intensity ◽  
Nuclear Spin Statistics ◽  
Tetrahedral Molecules ◽  
Integrated Intensities

A general expression is derived for the integrated intensity of rotational transitions in the vibronic ground state of tetrahedral molecules, taking into account the nuclear spin statistics. It is shown that the ratio of this expression to previously published spin-free integrated intensities depends only on the tensor character N of the operator driving the transition, the appropriate rotational quantum numbers J and J′, and the nuclear spin IB of the identical nuclei. Tables are given for N = 3, 4 and J ≤ 50 which enable the calculation of integrated intensities for octopole and hexadecapole collision induced dipole moment transitions, centrifugal distortion induced dipole moment transitions, and centrifugal distortion induced anisotropic polarizability tensor Raman transitions. It is shown that the relative error of the spin-free integrated intensity calculation is proportional to (2IB + 1)−2.

THE INFRARED SPECTRUM OF CARBON MONOXIDE IN CO–He MIXTURES AT HIGH PRESSURES

1965 ◽  
Vol 43 (4) ◽  
pp. 547-556 ◽  
Author(s):  
R. L. Armstrong ◽  
H. L. Welsh
Keyword(s):  
Carbon Monoxide ◽  
Infrared Spectrum ◽  
High Pressures ◽  
Intermolecular Forces ◽  
Molecular Rotation ◽  
Moment Analysis ◽  
Induced Absorption ◽  
Absolute Intensities ◽  
The Absolute ◽  
Integrated Intensities

The 1–0 and 2–0 infrared bands of carbon monoxide were measured in CO–He mixtures at pressures up to 3 000 atm at 295 °K. Extrapolation of the integrated intensities of the bands gave the absolute intensities, Γ01 = 2 686 ± 44 and Γ02 = 9.29 ± 0.27 cm2 per mole. A slight increase in the band intensities with pressure is due to apparent induced absorption. A moment analysis of the bands, as proposed by Gordon, shows the presence of a torque due to intermolecular forces which hinders the molecular rotation; the magnitude of the torque derived from the analysis varies linearly with the density of the perturbing gas.

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