Pith. sign in

REVIEW 2 major objections 5 minor 32 references

Rotational excitation cross sections for chloronium based on a new 5D interaction potential with molecular hydrogen

T0 review · 2 major / 5 minor · reviewed 2026-08-10 · deepseek-v4-flash

Pith's one-line read The first H2 collision data for interstellar chloronium show that helium-based rates are off by up to an order of magnitude.

desk verdict First H2Cl+–H2 PES and scattering data, solid and useful, with an honest but untested caveat about omitting excited H2 levels. read the letter →

arxiv 2412.20808 v1 pith:XG4XOU73 submitted 2024-12-30 physics.chem-ph astro-ph.GAastro-ph.IM

classification physics.chem-phastro-ph.GAastro-ph.IM
keywords chloroniumH2Cl+rotationalexcitationclosecouplingpotentialenergysurfacenon-LTEradiativetransferinterstellarchemistryH2collisions
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper provides the first rotationally inelastic cross sections and thermal rate coefficients for chloronium (H2Cl+) colliding with molecular hydrogen, the most abundant collider in interstellar clouds. To obtain them, the authors build a new five-dimensional rigid-rotor potential energy surface from explicitly correlated coupled-cluster calculations, fit it with a bispherical-harmonic expansion, and run numerically exact close-coupling scattering. The central result is that H2-collision rates differ strongly from the previously available helium-collision rates, often by an order of magnitude, with no simple linear scaling between the two. The authors conclude that helium is not an acceptable proxy for H2 in radiative transfer models of H2Cl+, so the new data should replace it in interpreting chloronium observations.

What carries the argument

The load-bearing object is the new five-dimensional rigid-rotor potential energy surface for H2Cl+–H2, expanded as a bispherical-harmonic series and fitted to 117,000 CCSD(T)-F12b/aug-cc-pVTZ energies with counterpoise correction. The expansion coefficients, truncated to 228 angular functions (142 in the final dynamics), are interpolated in the intermolecular distance and extrapolated at short and long range, giving a fully analytic surface with a global minimum of about -1718 $cm^{-1}$. This surface is fed into the scattering program, which solves the close-coupling equations for rotational excitation; the comparison baseline is the published H2Cl+–He surface and rates. The deep well of the H2 surface and the dense resonances it produces are what make the H2 results differ from He, since the helium well is only about 260 $cm^{-1}$ deep.

What would settle it

Run the same close-coupling calculations with H2 j2=1 (ortho-H2) and j2=2 levels included in the rotational basis and recompute the state-to-state cross sections; if any rate coefficient changes by more than the claimed few percent, the central dataset and the He comparison would need revision.

Watch

Extended reading notes

Core claim

The paper claims that rotational excitation of H2Cl+ by H2 is far more efficient than by He, and the difference cannot be captured by any constant scaling factor. It computes state-to-state cross sections for the lowest nine rotational levels of both ortho- and para-H2Cl+ with ground-state para-H2 (j2=0), over collision energies from 0.1 to 500 $cm^{-1}$, and rate coefficients up to 50 K. The H2 results show a dense resonance structure, a clear propensity for $\Delta$-j = 0,1 and $\Delta$-k_a,k_c = 0,1 transitions, and rate coefficients systematically larger than the He results by factors ranging from about 6 to more than an order of magnitude, including reversals in the relative strength of specific transitions. Since the H2 data are much larger and differently ordered, using He rates in non-LTE models would misestimate chloronium abundances and excitation conditions.

Load-bearing premise

The load-bearing premise is that ground-state para-H2 (j2=0) collisions can stand in for all H2 collisions in cold clouds, and the few-percent error estimate for this truncation is taken from an analogous H3O+ study, not from H2Cl+ calculations.

Editorial extensions

If this is right

  • Radiative transfer models of chloronium should adopt H2-collision rates instead of He-based proxies; the factor-of-10 differences will change inferred H2Cl+ abundances in molecular clouds.
  • The new rate coefficients, which often decrease with temperature rather than increase, will alter non-LTE predictions in warm regions where high-temperature rates are used.
  • The identified propensity rules (Delta-j = 0,1 and Delta-k_a,k_c = 0,1) can guide which transitions to include in reduced collisional models for chloronium.
  • For temperatures up to 50 K and rotational states up to about 125 cm^-1, the new data set provides the first direct collisional input for chloronium in dense-cloud chemistry.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A likely extension, not tested here, is that including H2 in j2=1 and j2=2 levels in the close-coupling basis could shift the rates by more than the few-percent error bars claimed, because that error estimate is borrowed from the H3O+–H2 system rather than computed for H2Cl+.
  • The deep well and dense resonances suggest a testable extension: at kinetic temperatures above 50 K, the rate coefficients may keep declining rather than flattening, which would matter for warm-cloud observations.
  • The absence of a universal H2/He scaling for H2Cl+ implies that for other hydride ions, helium-based collisional data should be re-examined per transition rather than rescaled by a single factor.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

2 major / 5 minor

Summary. The paper presents a new five-dimensional rigid-rotor potential energy surface for the interaction of H2Cl+ with H2, computed at the CCSD(T)-F12b/aug-cc-pVTZ level on 117,000 geometries and fitted with a 228-term bispherical expansion (reduced to 142 terms for dynamics). Using the MOLSCAT close-coupling code, the authors calculate state-to-state rotational excitation cross sections for ortho- and para-H2Cl+ in collision with ground-state para-H2 (j2=0) for kinetic energies up to 500 cm^-1, from which they derive thermal rate coefficients up to 50 K. They compare the results with existing He collider data and report large, non-linear differences, concluding that He is not a suitable proxy for H2. The PES fit and scattering convergence are carefully documented, and the collisional data are made available in the Supporting Information.

Significance. This work provides the first collisional data for chloronium with molecular hydrogen, a key input for non-LTE radiative transfer models of Cl chemistry in the interstellar medium. The ab initio protocol is state-of-the-art, the dataset is dense (117,000 points), and the analytical fit has sub-wavenumber RMS errors in the well and long range. The close-coupling calculations are converged to high precision (0.1% in jmax, 0.005% in Jtot), and the energy grid (0.1 cm^-1) resolves the resonance structure. The open availability of the PES and cross sections in the SI is a further strength. However, the validity of the j2=0-only restriction for representing all H2 collisions is a load-bearing assumption that is not independently tested for this system.

major comments (2)
  1. [Section 3 (Scattering calculations)] The paper's central claim of providing 'H2' collisional data rests on the assumption that restricting H2 to its j2=0 level captures the collisional physics of H2Cl+ + H2 at the claimed accuracy. The error estimate of 'less than 10%, and usually a few percent at most' is transferred from the H3O+ – H2 study (Ref. 32) and is not derived for H2Cl+. Given the unusually deep global minimum (-1718 cm^-1) and the dense Feshbach/shape resonance structure (Figs. 4 and 5), the coupling to H2 rotational levels j2>0 could be amplified relative to the H3O+ case. The paper itself lists the 'restricted rotational basis of p-H2 (j2=0)' among the most significant error sources and caps the overall accuracy at 'always better than ~20%', so an unvalidated 10% estimate may significantly affect the astrophysical rate coefficients. I recommend that the authors either perform a set of test close-coupling calculations including j2=1 (even with a reduced PES expansion or at selected energies) to verify the error bound, or clearly restrict the title/abstract claims to p-H2 (j2=0) collisions and state that the data are not directly applicable to regions with a significant o-H2 fraction.
  2. [Abstract and Section 4 (Results & Discussion)] The conclusion that He is not a suitable proxy for H2 is based solely on j2=0 p-H2 calculations. Since o-H2 (j2=1) has a non-spherical charge distribution and can open additional inelastic channels, the magnitude and scaling of the differences vs. He could differ for o-H2 collisions. The claim that 'the interaction with o-H2 (j2=1) or excited p-H2 (j2=2) leads to very similar cross sections to those with ground-state p-H2, so that calculations explicitly targeting these levels are not relevant' (Section 3) is presented without direct evidence for this system. Please either validate this statement or soften it to acknowledge the conditional nature of the He-proxy conclusion.
minor comments (5)
  1. [Section 3 (Scattering calculations)] The rotational constant C is given as 148.1004 MHz; from Ref. 13 and the stated internal energies, it should be 148.1004 GHz. Please correct this typo.
  2. [Abstract and Conclusions] The phrase 'proves again' is too strong for a single-system comparison; consider using 'demonstrates' or 'confirms'.
  3. [Section 3 (Scattering calculations)] The statement that the overall accuracy of the cross sections is 'always better than ~20%' would benefit from a more explicit breakdown of the individual error contributions (ab initio, fit, basis truncation) or at least a reference to a detailed analysis, since it is used to justify the astrophysical applicability.
  4. [Section 4 (Results & Discussion)] In the comparison with He, the energy ranges and number of rotational states differ between the two datasets (j<=9 for He vs. j<=4 here). A brief statement of the restricted comparison range in the text would help readers appreciate the scope of the conclusion.
  5. [Supporting Information] The SI statement mentions the PES and expansion coefficients; it would be helpful to state explicitly that the full state-to-state cross sections and rate coefficients are available in machine-readable format.

Circularity Check

0 steps flagged · score 2.0 of 10

No significant circularity: cross sections are derived from an ab initio 5D PES via close-coupling scattering, with no target observable used to tune the fit; only a minor self-citation supports the j2=0 truncation error estimate.

full rationale

The derivation chain is feed-forward: CCSD(T)-F12b ab initio energies at 117,000 geometries produce an analytically fitted 5D PES; that PES enters MOLSCAT close-coupling calculations; the resulting state-to-state cross sections are Boltzmann-averaged to rate coefficients. No measured cross section or rate coefficient is used as input at any stage, and the global minimum is verified against an independent single-point ab initio calculation rather than any observable. The comparison with the H2Cl+ + He data of Mehnen et al. is a post-hoc benchmark, not an input. The only self-referential element is the justification for neglecting H2 rotational levels j2 > 0: in Section 3 (Scattering calculations) the paper states that the estimated error from this truncation 'should be less than 10%, and usually a few percent at most' and invokes the authors' prior H3O+–H2 study (Ref. 32) for the claim that o-H2 and excited p-H2 give similar cross sections to ground-state p-H2. This is a minor self-citation supporting an accuracy caveat for the astrophysical applicability of the p-H2-only rates; it does not enter the calculation of the p-H2 cross sections themselves. The central claim, the first H2Cl+ + p-H2 rotational excitation data from a new ab initio PES, remains independent of any fitted target result. No equation-level reduction of a prediction to an input or to a self-citation chain is present.

Assumptions & free parameters 2 free parameters · 6 assumptions · 0 invented entities

The paper introduces no new physical entities. Its central output is a fitted PES, whose expansion coefficients and extrapolation parameters are the main fitted quantities. The most consequential assumption is the restriction to para-H2 (j2=0) with no direct H2Cl+ test of the j2>0 correction.

free parameters (2)
  • PES expansion coefficients v_{l1 m1 l2 l}(R), 228 selected functions = Not tabulated in text; provided as Supporting Information at https://doi.org/10.1021/acs.jpca.4c07467
    Least-squares fitted to 117,000 CCSD(T)-F12b/aug-cc-pVTZ interaction energies. These coefficients define the entire interaction potential used in the scattering calculations.
  • Short-range and long-range extrapolation parameters (A, alpha, B, beta) = Not reported; determined by interpolation to the three nearest ab initio distances
    Used to extrapolate the fitted expansion coefficients below R=3.25 bohr and above R=40 bohr, affecting the scattering dynamics at high and low collision energies.
assumptions (6)
  • domain assumption CCSD(T)-F12b/aug-cc-pVTZ interaction energies accurately describe the ground-state H2Cl+-H2 potential energy surface.
    No benchmark against higher-level theory or experiment is provided; this is the standard method choice in the paper, invoked in the 'Ab initio calculations' section.
  • domain assumption The rigid-rotor approximation is valid: freezing the Cl-H and H-H bond lengths neglects vibrational motion.
    Justified by the lowest vibrational frequency of H2Cl+ (1184.6 cm-1) being far above the collision energies studied (0.1-500 cm-1); stated in the Methods section.
  • domain assumption The bispherical harmonic expansion with l1<=15/16 and l2<=6, truncated to 228 terms, faithfully represents the ab initio PES.
    The RMS fit error is reported below 1 cm-1 in the well and long range, but this is a self-consistency check on the same ab initio data, not an independent validation.
  • domain assumption H2 rotational levels j2>0 can be neglected; p-H2 (j2=0) results approximate o-H2 and excited p-H2 collisions within about 10%.
    Stated in the 'Scattering calculations' section; supported only by reference to a prior H3O+ + H2 study (Ref. 32), not by direct calculation for H2Cl+.
  • standard math The close-coupling scattering method and Maxwell-Boltzmann thermal averaging are exact for the given PES.
    Standard quantum scattering formalism used via MOLSCAT; convergence tests are reported for jmax, Jtot, and radial propagation parameters.
  • domain assumption The rotational levels of H2Cl+ are correctly described by the spectroscopic constants of Araki et al.
    These constants set the channel energies in the scattering calculation. The text contains a typo (C = 148.1004 MHz should be GHz), but Table 1 energies follow the standard values.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Rotational excitation cross sections for chloronium based on a new 5D interaction potential with molecular hydrogen." pith.science (2026). https://pith.science/paper/XG4XOU73

@misc{pith2026241220808,
  author       = {Pith},
  title        = {Pith review of: Rotational excitation cross sections for chloronium based on a new 5D interaction potential with molecular hydrogen},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/XG4XOU73}},
  note         = {Machine review of arXiv:2412.20808}
}
abstract

Chloronium (H$_2$Cl$^+$) is an important intermediate of Cl-chemistry in space. The accurate knowledge of its collisional properties allows a better interpretation of the corresponding observations in interstellar clouds and therefore a better estimation of its abundance in these environments. While the ro-vibrational spectroscopy of H$_2$Cl$^+$ is well known, the studies of its collisional excitation are rather limited and these are available for the interaction with helium atoms only. We provide a new 5-dimensional rigid-rotor potential energy surface for the interaction of H$_2$Cl$^+$ with H$_2$, calculated from explicitly correlated coupled cluster ab initio theory, which was fitted then with a set of analytical functions, allowing to perform scattering calculations using accurate quantum theories. We analyze the collision-energy-dependence of the rotational state-to-state cross sections and the temperature dependence of the corresponding thermal rate coefficients, with a particular attention on the collisional propensity rules. When comparing our results for collisions with H$_2$ with those obtained with He as a colliding partner, we found very significant differences with non-linear scaling trends, which proves again that He is not a suitable proxy for collisions between hydride molecules and molecular hydrogen, the most abundant gas particle in the interstellar medium.

Figures

Figures reproduced from arXiv: 2412.20808 by the authors.

Figure 1
Figure 1. The 5D coordinate system for the H2Cl+ – H2collision. Analytical fit of the potential energy surface In order to efficiently use the PES for time-independent quantum close-coupling scattering calculations, it is convenient to employ a bispherical harmonic expansion. We used the convention proposed for the similar H2O − H2 collision, 15,16 where V (R, θ, ϕ, θ′ , ϕ′ ) = X l1m1l2l vl1m1l2l(R)tl1m1l2l(θ, ϕ, θ′ , ϕ′ ), (… view at source ↗
Figure 2
Figure 2. Angular dependence contour plots for the H [PITH_FULL_IMAGE:figures/full_fig_p009_2.png] view at source ↗
Figure 3
Figure 3. Radial dependence contour plots for the H [PITH_FULL_IMAGE:figures/full_fig_p010_3.png] view at source ↗
Figures from the paper (3 more)
Figure 4
Figure 4. Figure 4: (a)-(b) shows the collision-energy-dependence of the cross sections for [PITH_FULL_IMAGE:figures/full_fig_p014_4.png]
Figure 5
Figure 5. Figure 5: Collision-energy-dependence of the cross sections for all de-excitation transitions [PITH_FULL_IMAGE:figures/full_fig_p015_5.png]
Figure 6
Figure 6. Figure 6: Temperature-dependence of the state-to-state rate coefficients for [PITH_FULL_IMAGE:figures/full_fig_p017_6.png]

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

32 extracted references · 32 canonical work pages

  1. [1]

    C.; Bonah, L.; Asvany, O.; Brünken, S.; Schlemmer, S

    Thorwirth, S.; Steenbakkers, K.; Danowski, T.; Schmid, P. C.; Bonah, L.; Asvany, O.; Brünken, S.; Schlemmer, S. Gas- Phase Infrared Action Spectroscopy of CH2Cl + and CH3ClH +: Likely Protagonists in Chlorine Astrochemistry . Molecules 2024, 29, 665

  2. [2]

    Gas-grain Fluorine and Chlorine Chemistry in the Interstellar Medium

    Acharyya, K.; Herbst, E. Gas-grain Fluorine and Chlorine Chemistry in the Interstellar Medium . The Astrophysical Journal 2017, 850, 105

  3. [3]

    Wallström, S. H. J.; Muller, S.; Roueff, E.; Le Gal, R.; Black, J. H.; Gérin, M. Chlorine-bearing molecules in molecular absorbers at intermediate redshifts. Astronomy & Astrophysics 2019, 629, A128

  4. [4]

    C.; Pearson, J

    Lis, D. C.; Pearson, J. C.; Neufeld, D. A.; Schilke, P.; Müller, H. S. P.; Gupta, H.; Bell, T. A.; Comito, C.; Phillips, T. G.; Bergin, E. A. et al. Herschel /HIFI discovery of interstellar chloronium (H2Cl+). Astronomy and Astrophysics 2010, 521, L9

  5. [5]

    A.; Black, J

    Neufeld, D. A.; Black, J. H.; Gerin, M.; Goicoechea, J. R.; Goldsmith, P. F.; Gry, C.; Gupta, H.; Herbst, E.; Indriolo, N.; Lis, D. et al. Herschel Observations of Interstellar Chloronium . II . Detections Toward G29 .96-0.02, W49N , W51 , and W3 ( OH ), and Determinations of the Ortho - To - Para and ^ 35 Cl / ^ 37 Cl Isotopic Ratios . The Astrophysical ...

  6. [6]

    A.; Roueff, E.; Snell, R

    Neufeld, D. A.; Roueff, E.; Snell, R. L.; Lis, D.; Benz, A. O.; Bruderer, S.; Black, J. H.; De Luca, M.; Gerin, M.; Goldsmith, P. F. et al. Herschel Observations of Interstellar Chloronium . The Astrophysical Journal 2012, 748, 37

  7. [7]

    H.; Guelin, M.; Henkel, C.; Combes, F.; Gerin, M.; Aalto, S.; Beelen, A.; Darling, J.; Horellou, C

    Muller, S.; Black, J. H.; Guelin, M.; Henkel, C.; Combes, F.; Gerin, M.; Aalto, S.; Beelen, A.; Darling, J.; Horellou, C. et al. Detection of chloronium and measurement of the 35Cl / 37Cl isotopic ratio at z=0.89 toward PKS1830 -211. Astronomy & Astrophysics 2014, 566, L6

  8. [8]

    The ortho-to-para ratio of H _ 2 Cl ^ + : Quasi -classical trajectory calculations and new simulations in light of new observations

    Le Gal, R.; Xie, C.; Herbst, E.; Talbi, D.; Guo, H.; Muller, S. The ortho-to-para ratio of H _ 2 Cl ^ + : Quasi -classical trajectory calculations and new simulations in light of new observations. Astronomy & Astrophysics 2017, 608, A96

Show all 32 references
  1. [9]

    M.; Brown, J

    Ritchey, A. M.; Brown, J. M.; Federman, S. R.; Sonnentrucker, P. A Reexamination of Phosphorus and Chlorine Depletions in the Diffuse Interstellar Medium*. The Astrophysical Journal 2023, 948, 139

  2. [10]

    M.; Żuchowski, P.; Hochlaf, M

    Mehnen, B.; Hendaoui, H.; Ajili, Y.; Al-Mogren, M. M.; Żuchowski, P.; Hochlaf, M. Rotational Excitation and De - Excitation of Interstellar Chloronium Cation in Collisions with Helium Atoms . Monthly Notices of the Royal Astronomical Society 2024, 529, 2753--2762

  3. [11]

    K.; Amano, T.; Kawaguchi, K.; Oldani, M

    Lee, S. K.; Amano, T.; Kawaguchi, K.; Oldani, M. Difference-frequency laser spectroscopy of the 1 and 3 fundamental bands of H2Cl+: Determination of the equilibrium molecular structure. Journal of Molecular Spectroscopy 1988, 130, 1–19

  4. [12]

    Anharmonic potential-energy surfaces, vibrational frequencies and infrared intensities calculated from highly correlated wavefunctions

    Botschwina, P. Anharmonic potential-energy surfaces, vibrational frequencies and infrared intensities calculated from highly correlated wavefunctions. Journal of the Chemical Society, Faraday Transactions 2 1988, 84, 1263

  5. [13]

    Submillimeter- Wave Spectra of H2Cl + and its Isotopic Species : Molecular Structure

    Araki, M.; Furuya, T.; Saito, S. Submillimeter- Wave Spectra of H2Cl + and its Isotopic Species : Molecular Structure . Journal of Molecular Spectroscopy 2001, 210, 132--136

  6. [14]

    Afansounoudji, K. M. R.; Issa, R.; Sodoga, K.; Lauvergnat, D. Vibrational transitions of H 2 Cl + : Potential energy surface and anharmonic computations. Chemical Physics Letters 2023, 833, 140914

  7. [15]

    R.; Maluendes, S.; McLean, A

    Phillips, T. R.; Maluendes, S.; McLean, A. D.; Green, S. Anisotropic rigid rotor potential energy function for H2O-H 2 . The Journal of Chemical Physics 1994, 101, 5824--5830

  8. [16]

    R12-calibrated H2O-H2 interaction: Full dimensional and vibrationally averaged potential energy surfaces

    Valiron, P.; Wernli, M.; Faure, A.; Wiesenfeld, L.; Rist, C.; Kedžuch, S.; Noga, J. R12-calibrated H2O-H2 interaction: Full dimensional and vibrationally averaged potential energy surfaces . The Journal of Chemical Physics 2008, 129, 134306

  9. [17]

    Faure, A.; Crimier, N.; Ceccarelli, C.; Valiron, P.; Wiesenfeld, L.; Dubernet, M. L. Quasi-classical rate coefficient calculations for the rotational (de)excitation of H2O by H2. Astronomy & Astrophysics 2007, 472, 1029–1035

  10. [18]

    Rotational excitation of the interstellar NH2 radical by H2

    Bouhafs, N.; Lique, F.; Faure, A.; Bacmann, A.; Li, J.; Guo, H. Rotational excitation of the interstellar NH2 radical by H2. The Journal of Chemical Physics 2017, 146, 064309

  11. [19]

    Dagdigian, P. J. Interaction of the H2S molecule with molecular hydrogen: Ab initio potential energy surface and scattering calculations. The Journal of Chemical Physics 2020, 152, 074307

  12. [20]

    Variational calculations of excited states with zero total angular momentum (vibrational spectrum) of H2 without use of the Born–Oppenheimer approximation

    Bubin, S.; Adamowicz, L. Variational calculations of excited states with zero total angular momentum (vibrational spectrum) of H2 without use of the Born–Oppenheimer approximation . The Journal of Chemical Physics 2003, 118, 3079--3082

  13. [21]

    B.; Knizia, G.; Werner, H.-J

    Adler, T. B.; Knizia, G.; Werner, H.-J. A simple and efficient CCSD(T)-F12 approximation. The Journal of Chemical Physics 2007, 127, 221106

  14. [22]

    J.; Knizia, G.; Manby, F

    Werner, H.-J.; Knowles, P. J.; Knizia, G.; Manby, F. R.; Sch \" u tz, M.; others MOLPRO, version 2015.1, a package of ab initio programs. 2015

  15. [23]

    J.; Knizia, G.; Manby, F

    Werner, H.-J.; Knowles, P. J.; Knizia, G.; Manby, F. R.; Sch \" u tz, M. Wiley Interdisciplinary Reviews: Computational Molecular Science 2012, 2, 242--253

  16. [24]

    Dunning, T. H. Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and hydrogen. The Journal of Chemical Physics 1989, 90, 1007–1023

  17. [25]

    Efficient use of the correlation consistent basis sets in resolution of the identity MP2 calculations

    Weigend, F.; Köhn, A.; Hättig, C. Efficient use of the correlation consistent basis sets in resolution of the identity MP2 calculations. The Journal of Chemical Physics 2002, 116, 3175–3183

  18. [26]

    An accurate 5D potential energy surface for H _3 O ^+ -- H _2 interaction

    Demes, S.; Lique, F.; Faure, A.; Rist, C. An accurate 5D potential energy surface for H _3 O ^+ -- H _2 interaction. The Journal of Chemical Physics 2020, 153, 094301, Citation Key: Demes2020

  19. [27]

    T.; Ben Khalifa, M.; Lique, F

    Demes, S.; Bop, C. T.; Ben Khalifa, M.; Lique, F. First close-coupling study of the excitation of a large cyclic molecule: collision of c- C _5 H _6 with He . Physical Chemistry Chemical Physics 2024, 26, 16829--16837

  20. [28]

    F.; Bernardi, F

    Boys, S. F.; Bernardi, F. The calculation of small molecular interactions by the differences of separate total energies. Some procedures with reduced errors . Molecular Physics 1970, 19, 553--566

  21. [29]

    A Monte Carlo error estimator for the expansion of rigid-rotor potential energy surfaces

    Rist, C.; Faure, A. A Monte Carlo error estimator for the expansion of rigid-rotor potential energy surfaces. Journal of Mathematical Chemistry 2012, 50, 588--601

  22. [30]

    M.; Sueur, C

    Hutson, J. M.; Sueur, C. R. L. MOLSCAT: a program for non-reactive quantum scattering calculations on atomic and molecular collisions. Computer Physics Communications 2019, 241, 9–18

  23. [31]

    M.; Dalgarno, A.; Bates, D

    Arthurs, A. M.; Dalgarno, A.; Bates, D. R. The theory of scattering by a rigid rotator. Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences 1960, 256, 540--551

  24. [32]

    Demes, S.; Lique, F.; Faure, A.; van der Tak, F. F. S. An accurate set of H _3 O ^+ -- H _2 collisional rate coefficients for non-LTE modelling of warm interstellar clouds. Monthly Notices of the Royal Astronomical Society 2022, 518, 3593–3605 mcitethebibliography jpca-2024-07...

Pith tools

Reviewed August 10, 2026 · model on record in the stance chip above.