Analytical Evaluation of the Maxwell–Boltzmann Velocity Average in Pressure-Broadened Half-Width Calculations

“…The calculations also evaluate the mean relative thermal velocity (mrtv) approximation to the half-width. It has been shown [32] that at $300 K the mrtv calculation and the velocity averaged calculation give results within a few percent of one another, however the difference between the two methods of calculation is dependent on temperature [33].…”

Section: Theoretical Calculationsmentioning

confidence: 98%

Diode laser spectroscopic measurements and theoretical calculations of line parameters of nitrogen-broadened water vapor overtone transitions in the 818–834nm wavelength region

Bandyopadhyay¹,

Ray²,

Ghosh³

et al. 2007

Journal of Molecular Spectroscopy

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“…The isotropic part of the atom-atom potential was used in Hamilton's equations of motion to solve for the trajectories of the collision pairs. The calculations included the real and imaginary components for the half-width and line shift coefficients and proper averaging over the velocity, both of which have been shown to be important[55][56][57][58][59].The parameters describing the electrostatic, induction, and London dispersion potentials (dipole moments, quadrupole moments, ionization potentials, etc.) are well known.…”

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confidence: 99%

Line parameters for CO2 broadening in the ν2 band of HD16O

Devi

Benner

Sung

et al. 2017

Journal of Quantitative Spectroscopy and Radiative Transfer

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CO 2-rich planetary atmospheres such as those of Mars and Venus require accurate knowledge of CO 2 broadened HDO half-width coefficients and their temperature dependence exponents for reliable abundance determination. Although a few calculated line lists have recently been published on HDO-CO 2 line shapes and their temperature dependences, laboratory measurements of those parameters are thus far non-existent. In this work, we report the first measurements of CO 2-broadened half-width and pressure-shift coefficients and their temperature dependences for over 220 transitions in the ν 2 band. Self-broadened half-width and self-shift coefficients at room temperature are also obtained for majority of these transitions. In addition, the first experimental determination of collisional line mixing has been reported for 11 transition pairs for HDO-CO 2 and HDO-HDO systems. These results were obtained by analyzing ten highresolution spectra of HDO and HDO-CO 2 mixtures at various sample temperatures and pressures recorded with the Bruker IFS-125 HR Fourier transform spectrometer at the Jet Propulsion Laboratory (JPL). Two coolable absorption cells with path lengths of 20.38 cm and 20.941 m were used to record the spectra. The various line parameters were retrieved by fitting all ten spectra simultaneously using a multispectrum nonlinear least squares fitting algorithm. The ν 2 and 2ν 2 −ν 2 transitions in the 1100−4100 cm-1 region were extracted from the HITRAN2012 database giving 2245 and 435 transitions, respectively. Modified Complex Robert-Bonamy formalism (MCRB) calculations were made for the half-width coefficients, their temperature dependence and the pressure shift coefficients for the HDO−CO 2 and HDO−HDO collision systems. MCRB calculations are compared with the measured values.

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Analytical Evaluation of the Maxwell–Boltzmann Velocity Average in Pressure-Broadened Half-Width Calculations

Cited by 20 publications

References 65 publications

Lineshapes of the 172 and 602GHz rotational transitions of HC15N

Lineshapes of the 172 and 602GHz rotational transitions of HC15N

Diode laser spectroscopic measurements and theoretical calculations of line parameters of nitrogen-broadened water vapor overtone transitions in the 818–834nm wavelength region

Line parameters for CO2 broadening in the ν2 band of HD16O

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