Rovibrational line-shape parameters for H2 in He and new H2-He potential energy surface

Thibault, Franck; Patkowski, Konrad; Żuchowski, Piotr S.; Jóźwiak, Hubert; Ciuryło, R.; Wcisło, Piotr

doi:10.1016/j.jqsrt.2017.08.014

Cited by 46 publications

(93 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They are obtained from dynamical calculations on a potential energy surface (PES). Recently, a very accurate ab initio PES for H 2 –He was published and refined, and within the Born–Oppenheimer approximation, the same potential is applicable for D 2 –He. Thus, close coupling calculations, very similar to the ones done in prior works, were performed on the latter PES.…”

Section: Application Of the Generalized Hess Methodsmentioning

confidence: 99%

“…We will only give here specific details. The D 2 rotational energy levels used here are the calculated values of Komasa et al A technical point of great importance, because we are dealing with pure rotational lines, is to take into account the centrifugal distorsion of the potential . Indeed, as the molecule rotates, especially as its rotational quantum number increases, its effective diameter increases.…”

Section: Application Of the Generalized Hess Methodsmentioning

confidence: 99%

“…ω R is a linear combination of ω A and another collision integral which describes the diffusion of the polarization of the spectral transition. So far, this formalism has been applied only to very few systems and was recently revived by Thibault et al for molecular hydrogen lines in a helium bath. The great interest of this formalism is that the spectral line shape function (see also Equation 12 of Thibault et al can be written in a quite simple analytical form, equivalent to a hard‐collision profile, with parameters that can be exactly derived from complex generalized spectroscopic cross sections that share the same formal structure.…”

Section: Application Of the Generalized Hess Methodsmentioning

confidence: 99%

“…So far, this formalism has been applied only to very few systems and was recently revived by Thibault et al for molecular hydrogen lines in a helium bath. The great interest of this formalism is that the spectral line shape function (see also Equation 12 of Thibault et al can be written in a quite simple analytical form, equivalent to a hard‐collision profile, with parameters that can be exactly derived from complex generalized spectroscopic cross sections that share the same formal structure. These cross sections, expressed in terms of CC scattering matrices elements, read:

\begin{matrix} right σ_{λ}^{q} (j_{i}, j_{f}; j_{i}, j_{f}; E_{k i n}) & left = \frac{π}{k^{2}} \sum_{J_{i}, J_{f}, l, l^{'}, \bar{l}, \bar{l^{'}}} [J_{i}] [J_{f}] {([l] [l^{'}] [\bar{l}] [\bar{l^{'}}])}^{1 / 2} {(i)}^{- l + l^{'} + \bar{l} - \bar{l^{'}}} \\ right & left \times (\begin{matrix} l & \overset{l}{true} & λ \\ 0 & 0 & 0 \end{matrix}) (\begin{matrix} l^{'} & \overset{l^{'}}{true} & λ \\ 0 & 0 & 0 \end{matrix}) [\begin{matrix} j_{i} & j_{i} \end{matrix}] \end{matrix}

…”

Section: Application Of the Generalized Hess Methodsmentioning

confidence: 99%

“…Assuming that the bath is at equilibrium, from these cross sections thermally averaged omega integrals are obtained:

ω_{λ}^{s, s^{'}} false(q false) = < v > \int d x x^{false(s + s^{'} + 2 false) false/ 2} e^{- x} σ_{λ}^{q} false(j_{i} j_{f}; E_{k i n} = x k_{B} T false)

with < v > the mean relative speed at a given temperature T ,

< v > = \sqrt{8 k_{B} T false/ π μ} .

Finally, the relaxation frequencies (in rad s −1 ) introduced above are defined by

ω_{A} = n_{b} ω_{0}^{00} false(q false)

and

ω_{R} = M_{a} ω_{A} + \frac{2}{3} n_{b} M_{b} ω_{1}^{11} false(q false)

with

M_{i} = \frac{m_{i}}{m_{a} + m_{b}},

where m a is the mass of the active molecule, m b the mass of the bath particle, and n b the number density of the bath. The identification of Hess' profile with hard‐collision type profiles (see Section 3.2 of Thibault et al) and references therein) leads to the following line shape parameters (in cm −1 atm −1 ):

γ_{0} = Re ((), ω_{A}) κ,

δ_{0} = Im ((), ω_{A}) κ,

…”

Section: Application Of the Generalized Hess Methodsmentioning

confidence: 99%

See 4 more Smart Citations

Testing the ab initio quantum‐scattering calculations for the D₂–He benchmark system with stimulated Raman spectroscopy

Martínez

Bermejo

Thibault

et al. 2018

J Raman Spectroscopy

Self Cite

View full text Add to dashboard Cite

This work presents a comparison between experimental and calculated values for the collisional line broadenings and shifts of the S0(0), S0(1), and S0(2) lines of the rotational Raman spectrum of D2 perturbed by He at 77, 195, and 300 K. The pure rotational Raman spectra were obtained by means of a stimulated Raman spectroscopy experimental setup. Close coupling dynamical calculations were performed on the most recent ab initio H2–He potential energy surface. The resulting scattering matrix elements implemented in the general Hess method allow us to provide pressure broadening, pressure shifting, and Dicke coefficients from 10 to 400 K. Experimental and calculated values agree well with each other.

show abstract

Section: Application Of the Generalized Hess Methodsmentioning

confidence: 99%

Section: Application Of the Generalized Hess Methodsmentioning

confidence: 99%

Section: Application Of the Generalized Hess Methodsmentioning

confidence: 99%

\begin{matrix} right σ_{λ}^{q} (j_{i}, j_{f}; j_{i}, j_{f}; E_{k i n}) & left = \frac{π}{k^{2}} \sum_{J_{i}, J_{f}, l, l^{'}, \bar{l}, \bar{l^{'}}} [J_{i}] [J_{f}] {([l] [l^{'}] [\bar{l}] [\bar{l^{'}}])}^{1 / 2} {(i)}^{- l + l^{'} + \bar{l} - \bar{l^{'}}} \\ right & left \times (\begin{matrix} l & \overset{l}{true} & λ \\ 0 & 0 & 0 \end{matrix}) (\begin{matrix} l^{'} & \overset{l^{'}}{true} & λ \\ 0 & 0 & 0 \end{matrix}) [\begin{matrix} j_{i} & j_{i} \end{matrix}] \end{matrix}

…”

Section: Application Of the Generalized Hess Methodsmentioning

confidence: 99%

“…Assuming that the bath is at equilibrium, from these cross sections thermally averaged omega integrals are obtained:

ω_{λ}^{s, s^{'}} false(q false) = < v > \int d x x^{false(s + s^{'} + 2 false) false/ 2} e^{- x} σ_{λ}^{q} false(j_{i} j_{f}; E_{k i n} = x k_{B} T false)

with < v > the mean relative speed at a given temperature T ,

< v > = \sqrt{8 k_{B} T false/ π μ} .

Finally, the relaxation frequencies (in rad s −1 ) introduced above are defined by

ω_{A} = n_{b} ω_{0}^{00} false(q false)

and

ω_{R} = M_{a} ω_{A} + \frac{2}{3} n_{b} M_{b} ω_{1}^{11} false(q false)

with

M_{i} = \frac{m_{i}}{m_{a} + m_{b}},

γ_{0} = Re ((), ω_{A}) κ,

δ_{0} = Im ((), ω_{A}) κ,

…”

Section: Application Of the Generalized Hess Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Testing the ab initio quantum‐scattering calculations for the D₂–He benchmark system with stimulated Raman spectroscopy

Martínez

Bermejo

Thibault

et al. 2018

J Raman Spectroscopy

Self Cite

View full text Add to dashboard Cite

show abstract

References

2021

Collisional Effects on Molecular Spectra

View full text Add to dashboard Cite

Recent advances in collisional effects on spectra of molecular gases and their practical consequences

Hartmann

Tran

Armante

et al. 2018

Journal of Quantitative Spectroscopy and Radiative Transfer

Self Cite

View full text Add to dashboard Cite

Rovibrational line-shape parameters for H2 in He and new H2-He potential energy surface

Cited by 46 publications

References 51 publications

Testing the ab initio quantum‐scattering calculations for the D₂–He benchmark system with stimulated Raman spectroscopy

Testing the ab initio quantum‐scattering calculations for the D₂–He benchmark system with stimulated Raman spectroscopy

References

Recent advances in collisional effects on spectra of molecular gases and their practical consequences

Contact Info

Product

Resources

About

Rovibrational line-shape parameters for H2 in He and new H2-He potential energy surface

Cited by 46 publications

References 51 publications

Testing the ab initio quantum‐scattering calculations for the D2–He benchmark system with stimulated Raman spectroscopy

Testing the ab initio quantum‐scattering calculations for the D2–He benchmark system with stimulated Raman spectroscopy

References

Recent advances in collisional effects on spectra of molecular gases and their practical consequences

Contact Info

Product

Resources

About

Testing the ab initio quantum‐scattering calculations for the D₂–He benchmark system with stimulated Raman spectroscopy

Testing the ab initio quantum‐scattering calculations for the D₂–He benchmark system with stimulated Raman spectroscopy