Pith. sign in

REVIEW 4 major objections 5 minor 54 references

Measurements and simulations of rate coefficients for the deuterated forms of the H2 + + H2 and H3 + + H2 reactive systems at low temperature

T0 review · 4 major / 5 minor · reviewed 2026-08-11 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗ Review JSON

Pith's one-line read Laboratory trap measurements and kinetic simulations show that deuterated H3+ forms are hydrogenated more efficiently than astrochemical models assume, with the H2D+ + H2 back-reaction about four times faster at 100 K than the standard…

desk verdict Direct measurements are the real value here; the H2D+ + H2 factor-of-four claim is a transparently provisional model fit with an unresolved internal-excitation caveat. read the letter →

arxiv 2412.02206 v1 pith:V5FVLVUZ submitted 2024-12-03 astro-ph.SR astro-ph.GAnucl-exphysics.atom-phphysics.chem-ph

Miguel Jiménez-Redondo , Olli Sipilä , Pavol Jusko , Paola Caselli This is my paper · ORCID
classification astro-ph.SRastro-ph.GAnucl-exphysics.atom-phphysics.chem-ph
keywords astrochemistryion-moleculereactionsdeuteriumfractionationH3+chemistry22-poleiontrapratecoefficientslow-temperaturekineticsisotopicexchange
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 reports laboratory measurements of the rate coefficients for the deuterated variants of the H2+ + H2 and H3+ + H2 reactions between about 10 and 250 K, using a cryogenic 22-pole radio-frequency ion trap. The experiments show that the diatomic-ion processes run close to the ion-neutral capture-rate limit with little temperature dependence, while the isotopic exchange reactions of the triatomic ions change strongly with temperature. By fitting the measured ion-count time profiles with a kinetic chemistry code, the authors obtain a constrained value for one reaction they could not measure directly, H2D+ + H2 producing H3+ + HD, and find it about four times larger at 100 K than the value normally used in astrochemical models, while agreeing with that value near 20 K. If this is right, models of warmer interstellar gas destroy H2D+ and D2H+ too slowly, and they overestimate how much deuterium these ions carry into other molecules.

What carries the argument

The experimental engine is a cryogenic 22-pole radio-frequency ion trap, a device that holds mass-selected ions in an oscillating electric field while a helium buffer gas cools them and a measured density of H2 or D2 reacts with them; the decay of the primary ion population with storage time, measured at several neutral densities, gives the rate coefficient. Around this, the paper builds a kinetic chemistry code that evolves the whole network of the four H3+ isotopologs and fits the experimental time profiles by running an ensemble of 10,000 random realizations in which every rate coefficient is scaled by factors up to ten; the best chi-square fits provide the constrained rates. The simulation network is built by averaging spin-state-resolved rates assuming high-temperature statistical weights for nuclear spin states, and the measured coefficients are parameterized with the Arrhenius-Kooij formula so they can be inserted directly into models that do not track spin states.

What would settle it

Measure the rate coefficient of H2D+ + H2 to H3+ + HD directly at temperatures near 20, 60, and 100 K with a trap that can select H2D+ despite the mass-4 overlap with D2+, or that characterizes the ionic spin-state distribution; the simulation predicts agreement with the old value at 20 K and roughly four times that value at 100 K, so a measured rate that stays flat at the old value across that range would refute the central prediction.

Watch

Extended reading notes

Core claim

On the paper's own terms, the central result is a self-consistent set of low-temperature rate coefficients for the isotopic H2+/H3+ system, anchored by trap measurements and extended by simulation. The diatomic reactions follow the Langevin capture rate, the standard capture-rate limit for ion-neutral collisions. The triatomic exchange reactions are temperature dependent, with endothermic hydrogenation paths rising by about an order of magnitude from 15 to 250 K, partly because the internal energy of ortho-H2 helps pay for the endothermicity. The simulations reproduce the measured systems and, for the one unmeasured reaction that could be constrained, H2D+ + H2 to H3+ + HD, they predict a pronounced temperature dependence: essentially the old value at 20 K, but roughly four times that value at 100 K. The authors conclude that existing models may be underestimating the destruction efficiency of H2D+ and D2H+ and therefore overestimating their abundances and their role in deuterium fractionation in warmer environments, while stressing that a direct measurement is still needed.

Load-bearing premise

The simulations assume the ions' unseen nuclear spin states are populated in the high-temperature statistical proportions used to average the reaction network, and if the ion source produces a different spin mixture, all fitted rate coefficients, including the H2D+ + H2 prediction, would shift.

Editorial extensions

If this is right

  • Astrochemical models that keep the older literature values will destroy H2D+ and D2H+ too slowly above about 20 K, so they likely overproduce these ions and overstate deuterium fractionation in protostellar envelopes and other lukewarm gas.
  • The Arrhenius-Kooij parameters in Table 1 give modelers direct, spin-state-blind rate coefficients over 15-280 K for H2 reactants and 20-280 K for D2 reactants, without needing to resolve nuclear spin states.
  • The measured kinetic isotope effect, with rates decreasing as deuterium substitution increases, and the near-Langevin behavior of the diatomic reactions refine ionic chemistry in cold plasmas, though the reactions with D2 as the neutral remain within a few tens of percent of earlier values.
  • The simulation effort confirms the measured rates for the directly observed systems but leaves only one unmeasured rate with tight constraints, H2D+ + H2 to H3+ + HD, which is the obvious target for a dedicated measurement.

Reading between the lines

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

  • Editorial inference: A direct consequence the authors leave implicit is that the predicted enhancement should be visible as lower H2D+ and D2H+ abundances relative to current model predictions in gas near 50-100 K, which can be tested with existing submillimeter line observations of protostellar envelopes.
  • Editorial inference: The spin-averaging assumption is also testable: measuring the H2D+ + H2 rate at a few temperatures would distinguish the paper's prediction from the older flat value and, if the prediction fails, would point the finger at the assumed spin-state distribution rather than at the measured trap data.
  • Editorial inference: The random-ensemble fitting approach could be inverted in future work: with a direct pinning down of the H2D+ + H2 rate, the comparison against spin-resolved networks would constrain the spin-state distribution actually delivered by the ion source.
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

4 major / 5 minor

Summary. This paper reports low-temperature (10-250 K) rate coefficients for several isotopologs of the H2+ + H2 and H3+ + H2 reactive systems, measured in a cryogenic 22-pole ion trap. The directly measured rates, obtained from exponential decays of primary ions, cover eight reactions plus the HeH+/HeD+ + H2 processes, and are parameterized with the Arrhenius-Kooij formula. To obtain rates not directly measurable due to mass-selection conflicts, the authors run an ensemble of pyRate chemical simulations with randomized rate-coefficient scalings and fit the simulated ion-number time profiles to the experimental data. From fits to the D3+ + H2 and D2H+ + H2 experiments, they infer a rate for H2D+ + H2 -> H3+ + HD that is about four times higher at 100 K than the commonly used Hugo et al. (2009) value, while agreeing near 20 K. The paper concludes that astrochemical models may underestimate the hydrogenation efficiency of deuterated H3+ forms, affecting deuterium fractionation predictions in warmer regions.

Significance. If the results hold, the paper provides a valuable set of laboratory rate coefficients for deuterated variants of the H2+ + H2 and H3+ + H2 systems in a temperature range directly relevant to astrochemistry. The direct measurements appear to be carefully executed, with stated systematic uncertainties of about 20% in neutral density and statistical errors from linear fits; the agreement with prior merged-beam and selected-ion flow-tube data at overlapping temperatures lends credibility to the experimental methodology. The most novel claim, however, is the simulation-derived factor-of-four enhancement of the H2D+ + H2 -> H3+ + HD rate at 100 K relative to Hugo et al. (2009). This claim is not a direct measurement but a fitted model parameter, and its reliability depends on the kinetic model's treatment of internal excitation and nuclear-spin states. The authors themselves call for corroboration; the astrochemical conclusions drawn in the abstract and conclusions extend beyond what the evidence securely supports.

major comments (4)
  1. [Section 2.2 and Section 3] Section 2.2 states that products of the exothermic reactions 'can possess some degree of internal excitation, unlike the buffer-cooled primary ions' and that 'this possibility must be taken into account when processing the full data.' However, the kinetic model in Section 3 uses a single thermal rate coefficient per reaction and contains no internal-energy coordinate. The key simulated rate, H2D+ + H2 -> H3+ + HD (reaction 4 in Table 3), is endothermic by roughly 230 K, so H2D+ formed in the D3+ + H2 and D2H+ + H2 experiments with even ~100 K internal excitation would react faster at 100 K by a factor on the order of e^(100/100) ≈ 2.7, comparable to the claimed factor of four. The paper therefore does not establish that the fitted value is the thermal rate relevant to astrochemical models; it may be an effective rate for internally hot H2D+. The authors should either include internal-energy relaxation or state-rate corrections in the model, or explicitly re-frame the derived rate as an upper bound/effective value and temper the astrochemical conclusions accordingly.
  2. [Section 3.1 and Figure 3] The reduced reaction network averages over nuclear-spin states assuming high-temperature statistical weights (Table 3), while Section 2.2 notes that the experiments do not resolve spin states and that the ion-source spin distribution is uncharacterized. Figure 3 shows that the averaged network deviates clearly from the spin-resolved network at 15 K, and although the simulations are first run at 21.6 K, the discrepancy regime is not far below that temperature. Since the fitted H2D+ + H2 rate is obtained from a global fit over the entire time profile, a non-statistical spin distribution of the ions produced in the source could bias the extracted rate coefficient, especially for the endothermic reverse reaction. Please quantify the sensitivity of the fitted reaction-4 rate to the assumed spin weights, for example by repeating the ensemble fitting with different spin distributions, or provide a reasoned argument for why this effect is negligible at the simulation temperatures.
  3. [Section 3.2] The statistical method used to derive the simulation-based rate coefficients is not robust enough to support the quoted predictive power. Each ensemble has 10^4 random scalings, but the 'good-fit' criterion is an arbitrarily chosen factor-of-two threshold in chi-square, and only 5-10 solutions typically pass it. The resulting error bars are therefore not proper confidence intervals, and the coverage of the 16-dimensional rate-coefficient space by a factor-of-ten random scaling is not characterized. The paper itself notes that the good-fit constraint is arbitrary and that the trends depend on the random seed. For the key claim about reaction 4, the authors should apply a more rigorous parameter estimation procedure (e.g., MCMC, which they mention) or, failing that, present the result as a tentative model-dependent estimate and soften the stronger statements in Section 4 that models 'may be overestimating' the abundances of H2D+ and D2H+.
  4. [Abstract and Section 4] The abstract and conclusions state that the reported rate coefficients 'suggest a more efficient hydrogenation of deuterated H3+ forms than usually assumed in astrochemical models.' This statement is largely driven by the simulation-derived enhancement of the H2D+ + H2 rate, which is not a directly measured quantity and, as argued above, may be affected by unmodeled internal excitation and spin-state averaging. The paper's own caveat in Section 3.3 ('the simulation prediction should be corroborated by experiments with a different setup or by theoretical calculations') is appropriate, but the abstract does not convey this level of uncertainty. The authors should either bring the caveat into the abstract and conclusions or strengthen the evidence for the thermal nature of the fitted rate.
minor comments (5)
  1. [Section 2.1] The word 'cyogenically' in the second paragraph appears to be a typo for 'cryogenically'.
  2. [Figure 1 caption] The caption states 'T = 59 K' for the D3+ + H2 experiment, but the main text in Section 2.2 refers to the same figure as being at 27 K. Please correct the inconsistency.
  3. [Section 3.3] The reliability assessment for the D3+ + H2 -> D2H+ + HD reaction is described in the text but would be clearer if the figure itself distinguished the less-reliable green points (e.g., with open symbols) rather than relying only on the caption.
  4. [Table 1] The table caption mentions reactions 'between 15-280 K (reactions with H2) and 20-280 K (reactions with D2)', but Figure 2 and the text mostly describe a range up to 250 K; please clarify the exact temperature coverage used for the fits.
  5. [Appendix B] The statement that error bars for the summed reactions 2 and 3 are not defined in each direction, preventing a well-defined use of the Barlow (2004) method, is helpful; consider adding a more direct statement of how this uncertainty is propagated into the final quoted rates.

Circularity Check

0 steps flagged · score 2.0 of 10

No significant circularity: the directly measured trap rate coefficients are independent; the simulation-constrained H2D+ + H2 rate is a fitted inference that the paper openly flags, not an input-equivalent construction.

full rationale

The central directly measured rate coefficients are derived from the exponential decay of primary ion signals and are independent of the kinetic model, so they are not circular. The paper's main new result, the H2D+ + H2 → H3+ + HD rate, is not directly measured; it is constrained by fitting a kinetic model to the D2H+ + H2 and D3+ + H2 experimental time profiles. This is a parameter-estimation exercise, not a derivation from an input that already contains the answer. The fiducial network is seeded from Sipilä et al. (2017) based on Hugo et al. (2009), but the authors explicitly vary every rate by a factor of ten each way and select the best fit by chi-square against the experimental data, so the final value is not forced by the prior. The paper also explicitly states that this rate 'should be corroborated by experiments with a different setup or by theoretical calculations,' acknowledging its fitted status. The acknowledged internal excitation of product ions and the uncharacterized spin-state distribution are limitations or correctness risks, not circular reductions. The only mild circularity is the statement in Section 3.4 that the simulations 'corroborate' the experimental findings because the simulated rates agree with the experimental ones, when those simulated rates were themselves selected to minimize chi-square against the same data; this is a self-consistency check rather than independent corroboration. Because the directly measured rates stand on their own and the H2D+ inference is honestly labeled, the overall circularity is minor.

Assumptions & free parameters 4 free parameters · 4 assumptions · 0 invented entities

The paper introduces no new physical entities. Its main derived quantity, the H2D+ + H2 rate, is a fitted model parameter rather than a direct measurement. The fit depends on the assumed spin-state distribution, the initial rates taken from Hugo et al. (2009) via Sipilä et al. (2017), and the arbitrary good-fit threshold.

free parameters (4)
  • Arrhenius-Kooij coefficients A, B, C for each measured reaction = Values in Table 1
    Fit of the measured temperature-dependent rate coefficients to the standard formula k(T) = A(T/300)^B exp(-C/T); used for direct implementation in astrochemical codes.
  • H2D+ + H2 -> H3+ + HD rate coefficient (reaction 4 in Table 3) = Not stated numerically; Fig. 5 shows roughly a factor of 4 above Hugo et al. (2009) at 100 K
    This is the main unmeasured rate 'constrained' by the pyRate chi-square fit to experimental ion-count time profiles, not determined by a direct measurement.
  • Good-fit chi-square threshold = Factor of 2 above the minimum chi-square
    Arbitrary threshold, set empirically in Sect. 3.2, used to select which simulations count as good fits and to derive error bars on fitted rates.
  • Random scaling range for each reaction rate coefficient = Factor of 10 up and down
    Chosen search range for the 10^4 simulation ensemble; affects which rates can be considered constrained and the spread of the best-fit values.
assumptions (4)
  • domain assumption Trapped ions are thermalized to the trap temperature by the He buffer gas.
    Sect. 2.1 states the He pulse slows and relaxes the ions; measured rates are interpreted as temperature-dependent thermal rate coefficients.
  • domain assumption Ionic nuclear spin states are not changed by collisions except for D2H+ + D2, and the source spin distribution is uncharacterized; the averaged network assumes high-temperature statistical weights.
    Sect. 2.2 and Sect. 3.1; this underpins the comparison of measured rates to spin-averaged Hugo et al. (2009) values and the simulation fit.
  • domain assumption Product ions formed in exothermic reactions can carry internal excitation, but the simulations treat subsequent reactions with thermal rate coefficients.
    Sect. 2.2 flags this possibility explicitly, but the simulation section does not describe how internal excitation is handled.
  • standard math The Langevin collision model describes the diatomic-ion reactions.
    Used as the baseline comparison for H2+ + H2-type reactions; supported by prior merged-beam experiments cited in Sect. 1.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Measurements and simulations of rate coefficients for the deuterated forms of the H2 + + H2 and H3 + + H2 reactive systems at low temperature." pith.science (2026). https://pith.science/paper/V5FVLVUZ

@misc{pith2026241202206,
  author       = {Pith},
  title        = {Pith review of: Measurements and simulations of rate coefficients for the deuterated forms of the H2 + + H2 and H3 + + H2 reactive systems at low temperature},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/V5FVLVUZ}},
  note         = {Machine review of arXiv:2412.02206}
}
read the original abstract

The rate coefficients of various isotopic variations of the H2+ + H2 and H3+ + H2 reactions in the 10-250 K temperature range were measured using a cryogenic 22 pole radio frequency ion trap. The processes involving diatomic ions were found to behave close to the Langevin rate, whereas temperature-dependent rate coefficients were obtained for the four isotopic exchange processes with triatomic ions. Fitting the experimental data using a chemical code allowed us in specific cases to constrain rate coefficients that were not directly measured in the ion trap. The reported rate coefficients suggest a more efficient hydrogenation of deuterated H3+ forms than usually assumed in astrochemical models, which might affect deuteration rates in warmer environments.

Figures

Figures reproduced from arXiv: 2412.02206 by the authors.

Figure 1
Figure 1. Experimental number of ions in the trap as a function of trapping time for the D3 + + H2 experiment at 27 K. Σ represents the sum of all ions. H2D + and D2H + undergo subsequent reactions with H2, eventually leading to the formation of H3 + . The experiments presented here did not resolve the spin state of the ions. Nevertheless, spin relaxation might take place in the trap for the less efficient reactions, which ar… view at source ↗
Figure 2
Figure 2. The error bars represent the standard deviation of the data fit. Measurements at the lowest and highest temperature usually present an increased uncertainty associated with the freezing of the reactant gas in the colder parts of the trap, which affects the reliability of the pressure measurements, or the presence of residual species such as water giving place to parasitic reactions, respectively. Overall, the main s… view at source ↗
Figure 3
Figure 3. Number of ions as a function of reaction time in a simulation mimicking the D3 + + H2 experiment, where the gas initially only consists of D3 + and H2. The results are shown for simulations run at 15 K (left) and 50 K (right). The solid lines represent simulations using the averaged rate coefficients, and the markers represent a simulation where spin states have been explicitly included, but summed over afterward. 5… view at source ↗
Figures from the paper (2 more)
Figure 4
Figure 4. Figure 4: Number of the four ions as a function of reaction time in the H3 + + D2 experiment at a temperature of 21.6 K and a D2 number den￾sity of 9.83×109 cm−3 . The solid lines represent the best-fitting simula￾tion results, and the markers with error bars represent the exper…
Figure 5
Figure 5. Figure 5: Rate coefficients of various reactions, as indicated above each panel, as a function of temperature. The filled red, orange, and green circles indicate simulated rate coefficients based on the H3 + +D2, D2H + +H2, and D3 + +H2 systems, respectively. The error bars are …

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

54 extracted references · 35 canonical work pages

  1. [1]

    Adams, N. G. & Smith, D. 1981, http://dx.doi.org/10.1086/159162 magenta , 248, 373

    work page doi:10.1086/159162 1981

  2. [2]

    2010, http://dx.doi.org/10.1063/1.3454658 magenta J

    Aguado, A., Barrag \'a n, P., Prosmiti, R., et al. 2010, http://dx.doi.org/10.1063/1.3454658 magenta J. Chem. Phys. , 133, 024306

    work page doi:10.1063/1.3454658 2010

  3. [3]

    2016 a , http://dx.doi.org/10.1063/1.4972130 magenta J

    Allmendinger, P., Deiglmayr, J., Höveler, K., Schullian, O., & Merkt, F. 2016 a , http://dx.doi.org/10.1063/1.4972130 magenta J. Chem. Phys. , 145, 244316

    work page doi:10.1063/1.4972130 2016

  4. [4]

    2016 b , http://dx.doi.org/10.1002/cphc.201600828 magenta ChemPhysChem , 17, 3596

    Allmendinger, P., Deiglmayr, J., Schullian, O., et al. 2016 b , http://dx.doi.org/10.1002/cphc.201600828 magenta ChemPhysChem , 17, 3596

    work page doi:10.1002/cphc.201600828 2016

  5. [5]

    Baer, M. & Ng, C. Y. 1990, http://dx.doi.org/10.1063/1.459359 magenta J. Chem. Phys. , 93, 7787

    work page doi:10.1063/1.459359 1990

  6. [6]

    2004, https://ui.adsabs.harvard.edu/abs/2004physics...6120B http://dx.doi.org/10.48550/arXiv.physics/0406120 magenta arXiv e-prints , physics/0406120

    Barlow , R. 2004, https://ui.adsabs.harvard.edu/abs/2004physics...6120B http://dx.doi.org/10.48550/arXiv.physics/0406120 magenta arXiv e-prints , physics/0406120

    arXiv doi:10.48550/arxiv.physics/0406120 2004

  7. [7]

    2010, http://dx.doi.org/10.1088/0004-637X/725/1/214 magenta ApJ , 725, 214

    Bayet, E., Awad, Z., & Viti, S. 2010, http://dx.doi.org/10.1088/0004-637X/725/1/214 magenta ApJ , 725, 214

    work page doi:10.1088/0004-637x/725/1/214 2010

  8. [8]

    2019, http://dx.doi.org/10.1098/rsta.2018.0401 magenta Phil

    Caselli, P., Sipil \"a , O., & Harju, J. 2019, http://dx.doi.org/10.1098/rsta.2018.0401 magenta Phil. Trans. R. Soc. London, Ser. A , 377, 20180401

    work page arXiv 2019

Show all 54 references
  1. [9]

    Caselli, P., van der Tak, F. F. S., Ceccarelli, C., & Bacmann, A. 2003, http://dx.doi.org/10.1051/0004-6361:20030526 magenta A&A , 403, L37

    2003 doi

  2. [10]

    I., Litvin, I., Nikitin, E

    Dashevskaya, E. I., Litvin, I., Nikitin, E. E., & Troe, J. 2016, http://dx.doi.org/10.1063/1.4972129 magenta J. Chem. Phys. , 145, 244315

    2016 doi

  3. [11]

    H., McClure, D

    Douglass, C. H., McClure, D. J., & Gentry, W. R. 1977, http://dx.doi.org/10.1063/1.434675 magenta J. Chem. Phys. , 67, 4931

    1977 doi

  4. [12]

    N., Schroeder I, I

    Drozdovskaya, M. N., Schroeder I, I. R. H. G., Rubin, M., et al. 2021, http://dx.doi.org/10.1093/mnras/staa3387 magenta , 500, 4901

    2021 doi

  5. [13]

    Eaker, C. W. & Schatz, G. C. 1985, http://dx.doi.org/10.1021/j100258a036 magenta J. Phys. Chem. , 89, 2612

    1985 doi

  6. [14]

    1992, http://dx.doi.org/10.1002/9780470141397.ch1 magenta Adv

    Gerlich, D. 1992, http://dx.doi.org/10.1002/9780470141397.ch1 magenta Adv. Chem. Phys. , LXXXII, 1

    1992 doi

  7. [15]

    2002, http://dx.doi.org/10.1016/S0032-0633(02)00094-6 magenta P&SS , 50, 1275

    Gerlich, D., Herbst, E., & Roueff, E. 2002, http://dx.doi.org/10.1016/S0032-0633(02)00094-6 magenta P&SS , 50, 1275

    2002 doi

  8. [16]

    2013, http://dx.doi.org/10.1021/jp400917v magenta J

    Gerlich, D., Pla s il, R., Zymak, I., et al. 2013, http://dx.doi.org/10.1021/jp400917v magenta J. Phys. Chem. A , 117, 10068

    2013 doi

  9. [17]

    & Schlemmer, S

    Gerlich, D. & Schlemmer, S. 2002, http://dx.doi.org/10.1016/S0032-0633(02)00095-8 magenta P&SS , 50, 1287

    2002 doi

  10. [18]

    2006, http://dx.doi.org/10.1098/rsta.2006.1865 magenta Phil

    Gerlich, D., Windisch, F., Hlavenka, P., Pla s il, R., & Glosik, J. 2006, http://dx.doi.org/10.1098/rsta.2006.1865 magenta Phil. Trans. R. Soc. London, Ser. A , 364, 3007

    2006

  11. [19]

    G., & Smith, D

    Giles, K., Adams, N. G., & Smith, D. 1992, http://dx.doi.org/10.1021/j100198a030 magenta J. Phys. Chem. , 96, 7645

    1992 doi

  12. [20]

    & Gerlich, D

    Glenewinkel-Meyer, T. & Gerlich, D. 1997, http://dx.doi.org/10.1002/ijch.199700039 magenta Isr. J. Chem. , 37, 343

    1997 doi

  13. [21]

    1994, http://dx.doi.org/10.1016/0168-1176(94)90004-3 magenta Int

    Glos \'i k, J. 1994, http://dx.doi.org/10.1016/0168-1176(94)90004-3 magenta Int. J. Mass Spectrom. Ion Processes , 139, 15

    1994 doi

  14. [22]

    2012, http://dx.doi.org/10.1063/1.4747548 magenta J

    G \'o mez-Carrasco , S., Gonz \'a lez-S \'a nchez , L., Aguado, A., et al. 2012, http://dx.doi.org/10.1063/1.4747548 magenta J. Chem. Phys. , 137, 094303

    2012 doi

  15. [23]

    Hily-Blant , P., Faure , A., Rist , C., Pineau des For \^e ts , G., & Flower , D. R. 2018, http://dx.doi.org/10.1093/mnras/sty881 magenta , 477, 4454 http://adsabs.harvard.edu/abs/2018MNRAS.477.4454H

    2018 doi

  16. [24]

    A., Schmutz, H., & Merkt, F

    H \"o veler, K., Deiglmayr, J., Agner, J. A., Schmutz, H., & Merkt, F. 2021 a , http://dx.doi.org/10.1039/D0CP06107G magenta Phys. Chem. Chem. Phys. , 23, 2676

    2021 doi

  17. [25]

    2021 b , http://dx.doi.org/10.1080/00268976.2021.1954708 magenta Mol

    H \"o veler, K., Deiglmayr, J., & Merkt, F. 2021 b , http://dx.doi.org/10.1080/00268976.2021.1954708 magenta Mol. Phys. , 119, e1954708

    2021

  18. [26]

    2009, http://dx.doi.org/10.1063/1.3089422 magenta J

    Hugo, E., Asvany, O., & Schlemmer, S. 2009, http://dx.doi.org/10.1063/1.3089422 magenta J. Chem. Phys. , 130, 164302

    2009 doi

  19. [27]

    J., & Tanarro, I

    Jiménez-Redondo, M., Carrasco, E., Herrero, V. J., & Tanarro, I. 2011, http://dx.doi.org/10.1039/C1CP20426B magenta Phys. Chem. Chem. Phys. , 13, 9655

    2011 doi

  20. [28]

    2024, http://dx.doi.org/10.1080/00268976.2023.2217744 magenta Mol

    Jusko, P., Jim\' e nez-Redondo, M., & Caselli, P. 2024, http://dx.doi.org/10.1080/00268976.2023.2217744 magenta Mol. Phys. , 122, e2217744

    2024

  21. [29]

    R., Lehmann, K

    Krenos, J. R., Lehmann, K. K., Tully, J. C., Hierl, P. M., & Smith, G. P. 1976, http://dx.doi.org/10.1016/0301-0104(76)89028-3 magenta Chem. Phys. , 16, 109

    1976 doi

  22. [30]

    McCall, B. J. & Oka, T. 2000, http://dx.doi.org/10.1126/science.287.5460.1941 magenta Sci , 287, 1941

    2000

  23. [31]

    2022, http://dx.doi.org/10.1021/acs.jpclett.1c03374 magenta J

    Merkt, F., Höveler, K., & Deiglmayr, J. 2022, http://dx.doi.org/10.1021/acs.jpclett.1c03374 magenta J. Phys. Chem. Lett. , 13, 864

    2022 doi

  24. [32]

    1972, http://dx.doi.org/10.1016/0031-8914(72)90223-6 magenta Physica , 60, 90

    Milenko, Y., Karnatsevich, L., & Kogan, V. 1972, http://dx.doi.org/10.1016/0031-8914(72)90223-6 magenta Physica , 60, 90

    1972 doi

  25. [33]

    Millar, T. J. 2002, http://dx.doi.org/10.1016/S0032-0633(02)00082-X magenta P&SS , 50, 1189

    2002 doi

  26. [34]

    J., Bennett, A., & Herbst, E

    Millar, T. J., Bennett, A., & Herbst, E. 1989, http://dx.doi.org/10.1086/167444 magenta , 340, 906

    1989 doi

  27. [35]

    J., Walsh, C., de Sande, M

    Millar, T. J., Walsh, C., de Sande, M. V., & Markwick, A. J. 2024, http://dx.doi.org/10.1051/0004-6361/202346908 magenta A&A , 682, A109

    2024 doi

  28. [36]

    2013, http://dx.doi.org/10.1021/cr400266w magenta Chem

    Oka, T. 2013, http://dx.doi.org/10.1021/cr400266w magenta Chem. Rev. , 113, 8738

    2013 doi

  29. [37]

    1996, http://dx.doi.org/10.1016/0301-0104(96)00160-7 magenta Chem

    Paul, W., Schlemmer, S., L \"u cke, B., & Gerlich, D. 1996, http://dx.doi.org/10.1016/0301-0104(96)00160-7 magenta Chem. Phys. , 209, 265

    1996 doi

  30. [38]

    E., Johnson, L

    Pollard, J. E., Johnson, L. K., Lichtin, D. A., & Cohen, R. B. 1991, http://dx.doi.org/10.1063/1.461704 magenta J. Chem. Phys. , 95, 4877

    1991 doi

  31. [39]

    , Polyansky, O

    Ramanlal, J. , Polyansky, O. L. , & Tennyson, J. 2003, http://dx.doi.org/10.1051/0004-6361:20030774 magenta A&A , 406, 383

    2003 doi

  32. [40]

    2015, http://dx.doi.org/10.1063/1.4937138 magenta J

    Sanz-Sanz , C., Aguado, A., Roncero, O., & Naumkin, F. 2015, http://dx.doi.org/10.1063/1.4937138 magenta J. Chem. Phys. , 143, 234303

    2015 doi

  33. [41]

    2020, http://dx.doi.org/10.1002/cphc.202000258 magenta ChemPhysChem , 21, 1429

    Savić, I., Schlemmer, S., & Gerlich, D. 2020, http://dx.doi.org/10.1002/cphc.202000258 magenta ChemPhysChem , 21, 1429

    2020 doi

  34. [42]

    2021, http://dx.doi.org/10.3847/1538-4357/ac289b magenta ApJ , 922, 206

    Shimonishi, T., Izumi, N., Furuya, K., & Yasui, C. 2021, http://dx.doi.org/10.3847/1538-4357/ac289b magenta ApJ , 922, 206

    2021 doi

  35. [43]

    2015 a , http://dx.doi.org/10.1051/0004-6361/201424364 magenta , http://adsabs.harvard.edu/abs/2015A

    Sipil \"a , O., Caselli , P., & Harju , J. 2015 a , http://dx.doi.org/10.1051/0004-6361/201424364 magenta , http://adsabs.harvard.edu/abs/2015A

    2015 doi

  36. [44]

    2017, http://dx.doi.org/10.1051/0004-6361/201731039 magenta , http://adsabs.harvard.edu/abs/2017A

    Sipil \"a , O., Harju , J., & Caselli , P. 2017, http://dx.doi.org/10.1051/0004-6361/201731039 magenta , http://adsabs.harvard.edu/abs/2017A

    2017 doi

  37. [45]

    2015 b , http://dx.doi.org/10.1051/0004-6361/201526468 magenta , http://adsabs.harvard.edu/abs/2015A

    Sipil \"a , O., Harju , J., Caselli , P., & Schlemmer , S. 2015 b , http://dx.doi.org/10.1051/0004-6361/201526468 magenta , http://adsabs.harvard.edu/abs/2015A

    2015 doi

  38. [46]

    V., Aguado, A., G \'o mez-Carrasco , S., & Roncero, O

    Suleimanov, Y. V., Aguado, A., G \'o mez-Carrasco , S., & Roncero, O. 2018, http://dx.doi.org/10.1021/acs.jpclett.8b00783 magenta J. Phys. Chem. Lett. , 9, 2133

    2018 doi

  39. [47]

    1995, http://dx.doi.org/10.1088/0034-4885/58/4/002 magenta Rep

    Tennyson, J. 1995, http://dx.doi.org/10.1088/0034-4885/58/4/002 magenta Rep. Prog. Phys. , 58, 421

    1995 doi

  40. [48]

    Theard , L. P. & Huntress , W. T. 1974, http://dx.doi.org/10.1063/1.1681453 magenta , 60, 2840 https://ui.adsabs.harvard.edu/abs/1974JChPh..60.2840T

    1974 doi

  41. [49]

    R., et al

    Verhaegh, K., Lipschultz, B., Harrison, J. R., et al. 2021, http://dx.doi.org/10.1088/1741-4326/ac1dc5 magenta Nucl. Fusion , 61, 106014

    2021 doi

  42. [50]

    2012, http://dx.doi.org/10.1088/0067-0049/199/1/21 magenta , 199, 21

    Wakelam, V., Herbst, E., Loison, J.-C., et al. 2012, http://dx.doi.org/10.1088/0067-0049/199/1/21 magenta , 199, 21

    2012 doi

  43. [51]

    Walmsley, C. M. & Flower, D. R. 2004, http://dx.doi.org/10.1051/0004-6361:20035718 magenta A&A , 418, 1035

    2004 doi

  44. [52]

    & Woods, P

    Willacy, K. & Woods, P. M. 2009, http://dx.doi.org/10.1088/0004-637X/703/1/479 magenta ApJ , 703, 479

    2009 doi

  45. [53]

    Woon , D. E. & Herbst , E. 2009, http://dx.doi.org/10.1088/0067-0049/185/2/273 magenta , 185, 273 https://ui.adsabs.harvard.edu/abs/2009ApJS..185..273W

    2009 doi

  46. [54]

    J., & Bowman, J

    Xie, Z., Braams, B. J., & Bowman, J. M. 2005, http://dx.doi.org/10.1063/1.1927529 magenta J. Chem. Phys. , 122, 224307

    2005 doi

Pith tools

Reviewed August 11, 2026 · model on record in the stance chip above.