Pith. sign in

REVIEW 4 major objections 5 minor 52 references

Size characterization of neutral rare-gas clusters based on time-resolved polarization anisotropy measurements

T0 review · 4 major / 5 minor · reviewed 2026-08-01 · deepseek-v4-flash

Pith's one-line read The mean size of neutral argon and neon clusters can be read from the dephasing of a molecule's rotational alignment, and the widely used Hagena scaling law needs a new large-cluster regime.

desk verdict Useful method paper, but the new Hagena scaling law rests on three data points and an assumed rotational temperature — suggestive, not yet solid. read the letter →

arxiv 2607.23064 v1 pith:DLSGJVSU submitted 2026-07-25 physics.atm-clus

classification physics.atm-clus PACS 36.40.-c
keywords clustersizedeterminationpolarizationanisotropyrotationalcoherencespectroscopyHagenascalinglawsupersonicexpansionargonclustersneonspherical-toprigidrotor
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 establishes that the mean size of neutral argon and neon clusters can be read from the rate at which the rotational alignment of a surface-attached phthalocyanine molecule dephases after a femtosecond pump pulse. Using a spherical-top rigid-rotor model for the ensemble, the authors extract cluster sizes in the range of roughly 50 to 10,000 atoms with sensitivity to changes of a few tens of atoms, and do so without ionizing the cluster, which avoids the fragmentation that plagues mass-spectrometric sizing. The measurements show that the widely used Hagena scaling law reproduces the data for small clusters but underestimates the mean size by a factor of two to four for argon clusters with a Hagena parameter Γ* above 3000, and by nearly an order of magnitude for neon. The paper proposes a new scaling regime, ⟨n⟩ = 22 (Γ*/1000)^3.5, for the large-cluster range, and suggests an adjusted q parameter (0.9) for neon. If correct, the result gives experimenters a more accurate ionization-free ruler for rare-gas cluster sizes and refines the scaling law used across cluster physics.

What carries the argument

The central object is the rotational-coherence anisotropy signal r(T) = (2/5)⟨P2[µ(0)·µ(T)]⟩, expressed for a spherical-top rigid rotor by Eq. (9): a thermal Boltzmann sum over angular momentum states J, where the rotational constant B_n encodes the cluster size (n) and the dephasing time scales roughly as sqrt(m/T_rot). The key identity is that for large enough clusters the quantum sum can be replaced by a semi-classical frequency-domain integral, computable by FFT, which reduces the fit cost by about five orders of magnitude. The cluster size enters through the moment of inertia, modeled as a homogeneous sphere with an effective mass that includes the dopant, I_n = (2/5 n M_at + 2/3 M_H2Pc

What would settle it

Measure the rotational temperature of the clusters independently under the same expansion conditions (e.g. by rotationally resolved spectroscopy of the H2Pc dopant); if T_rot differs from the assumed 37 K for Ar or 10 K for Ne, the extracted mean sizes shift by the square root of the ratio, changing the fitted coefficients a and b in the proposed scaling law and potentially eliminating the claimed deviation from Hagena.

Watch

Extended reading notes

Core claim

The central claim is that the initial dephasing of the polarization anisotropy of an ensemble of surface-doped rare-gas clusters carries a precise, quantitative readout of the mean cluster size. Treating each doped cluster as a spherical-top rigid rotor with a transition dipole fixed along a body axis, the authors derive an analytical expression for the anisotropy r(T) — a thermal average over rotational states whose frequency content narrows as the cluster grows — and invert it by least-squares fitting to pump-probe data on phthalocyanine-doped Ar and Ne clusters. The resulting mean sizes track the Hagena scaling law for small clusters (Γ* up to about 3000) but lie systematically above it f

Load-bearing premise

The extracted sizes assume the rotational temperature of the clusters equals the vibrational temperature taken from prior experiments (37 K for Ar, 10 K for Ne); the dephasing time scales as the square root of that temperature, so any error shifts every reported cluster size.

Editorial extensions

If this is right

  • The Hagena scaling law, as commonly used, systematically underestimates mean cluster sizes for Γ* > 3000 (Ar) and for Ne generally; the proposed piecewise law gives better size estimates for continuous supersonic expansions.
  • The technique provides an ionization-free, fragmentation-free way to size neutral rare-gas clusters between roughly 50 and 10,000 atoms, with sensitivity to differences of a few tens of atoms, making it a calibration tool for cluster-isolated reaction studies and collective processes.
  • The anisotropy model, with the spherical-top treatment and FFT acceleration, can be directly applied to other molecular dopants and other rare gases (except helium droplets) to obtain cluster sizes from a single time-resolved measurement.
  • The extracted sizes constrain the empirical parameter q in Hagena's formula; the paper's value q_Ne = 0.9 suggests that q is gas- and expansion-condition dependent, not universal.

Reading between the lines

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

  • If the T_rot = T_vib assumption is relaxed, the reported sizes likely shift upward (the authors note this); a direct measurement of T_rot would allow the new scaling law to be recalibrated without waiting for cluster size standards.
  • The sensitivity of the method may extend to measuring the width (σ) of the cluster size distribution, not just its mean; the paper fits σ but does not discuss its precision or its covariance with ⟨n⟩, so a careful error analysis could turn the technique into a distribution-shape probe.
  • Because the dephasing time scales as sqrt(m/T_rot), the same measurement could serve as a rotational thermometer if the cluster size is known independently, effectively inverting the method.
  • The method could be adapted to pulsed jets by modeling non-equilibrium rotational states, which the paper leaves as future work; if the anisotropy dephasing in pulsed expansions also follows the spherical-top model, the scaling law could be extended to a regime where many cluster experiments operate.
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. The manuscript reports an ionization-free method for sizing neutral rare-gas clusters (Ar and Ne) by measuring the time-resolved polarization anisotropy of a surface-deposited H2Pc chromophore. A rigid-rotor model for spherical tops (Eqs. 6–9) relates the initial anisotropy dephasing to the mean cluster size and width of a log-normal size distribution, assuming a rotational temperature equal to a literature vibrational temperature. Mean sizes are extracted for eight Ar and three Ne expansion conditions (Fig. 5). The paper then proposes a revised Hagena scaling law for Γ* > 3000, ⟨n⟩ = a(Γ*/1000)^b with a = 22 ± 5 and b = 3.5 ± 0.3 (Eq. 15), and suggests q_Ne = 0.9 to reconcile the Ne data.

Significance. The experimental approach is attractive and timely: it avoids the fragmentation artifacts of mass-spectrometric sizing and demonstrates sensitivity to mean cluster size via a soft optical probe. The analytical FFT-based implementation of the rotational-coherence model is a genuine methodological advance and should be useful to the cluster and molecular-beam communities. If the size calibration were independently validated, the revised Hagena law would be a practically useful correction. However, the strength of the paper at present lies more in the method than in the new scaling exponent, because the headline result rests on a very small number of points and on an unmeasured rotational temperature.

major comments (4)
  1. [Section III, Eq. (15), Fig. 5b] The revised Hagena law is a two-parameter fit to only three Ar points (⟨n⟩ ≈ 1091, 1470, 1984; Γ* > 3000), leaving one degree of freedom. The quoted uncertainty b = 3.5 ± 0.3 is the statistical fit error and does not include systematic uncertainty in T_rot. Since the extracted size scales as n ∝ τ^{6/5} T_rot^{3/5}, a common error in T_rot changes only the prefactor a, but any condition-dependent variation of T_rot (for example, the three points have stagnation temperatures of 190, 207, and 191 K, or size-dependent evaporative rotational cooling) rescales the points unevenly and directly biases b. With three points and no internal cross-check, the new scaling regime is not yet established. Please add additional data points, an in-situ T_rot constraint, or a quantitative sensitivity analysis showing that b is stable under plausible T_rot variations.
  2. [Section IV, Eqs. (8)–(9)] The absolute cluster sizes in Fig. 5 rest on the assumption T_rot = T_vib, with T_Ar = 37 K and T_Ne = 10 K taken from Ref. [46], which was measured on a different apparatus and for different expansion conditions. The authors explicitly concede that an underestimate of T_rot would mean 'the real cluster sizes might be higher' than reported. This is load-bearing: both the Boltzmann weights in Eq. (9) and the dephasing time scale as functions of T_rot, so all extracted sizes, and thus the fitted a and b in Eq. (15), inherit this uncertainty. The manuscript should propagate a plausible range of T_rot through the size extraction and into the scaling-law fit, or otherwise justify why the literature temperatures apply to all eight Ar conditions.
  3. [Section III, last paragraph, Fig. 5c] The value q_Ne = 0.9 is introduced post hoc, after the Ne data show a deviation of 'almost an order of magnitude,' and it is chosen so that the Ne points agree with the Ar-based adjusted scaling. Since q enters the definition of Γ* in Eq. (1), tuning q against the same data that are used to support the scaling law is circular and does not validate either q_Ne or the proposed exponent. The Ne comparison should be made with q_Ne fixed a priori, or q_Ne should be treated as a fitted parameter with a reported uncertainty and some form of cross-validation.
  4. [Section III, Fig. 4a] The smallest Ar condition (⟨n_Hag⟩ = 59) is not described by the model at early delay times, and the paper attributes this to angular-momentum transfer during doping, i.e., a breakdown of the assumed rotational equilibrium. This is precisely the small-size regime for which the paper claims 'sensitivity to small changes in the mean cluster size of just a few tens of atoms.' As written, the one point where the method can be checked against the Hagena law at small n is the point where the model fails. The authors should either quantify the doping-induced angular-momentum effect and correct for it, or explicitly restrict the sensitivity claim to larger clusters.
minor comments (5)
  1. [Near Eq. (15)] The text says the fitted curve is 'shown in Fig. 4b'; it should probably be Fig. 5b. Please check all cross-references to figures.
  2. [Section II A] The quantity d·T_cl in the discussion of expansion conditions is not defined; presumably d is the nozzle diameter and T_cl some cluster temperature, but it should be stated.
  3. [Fig. 5b] The 'empirical confidence interval' is not defined. Indicate whether it is the fit covariance, a bootstrap interval, and whether it includes systematic T_rot uncertainty.
  4. [Section III / Eq. (10)–(13)] The log-normal widths σ_Ar = 1.0 and σ_Ne = 0.8 are fixed when reporting extracted mean sizes. A short sensitivity study showing how ⟨n⟩ changes for, say, σ = 0.8–1.2 would help, because a broad log-normal distribution shifts the mean relative to the median.
  5. [Section IX] The data availability statement says 'Accession codes will be available before publication.' For a manuscript whose conclusions depend on fits to experimental decays, please provide an anonymous repository link or a clear statement of when and where the data will be released.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: extracted cluster sizes come from an independent rigid-rotor model, and the revised Hagena scaling law is an empirical fit to those independently determined sizes.

full rationale

The derivation chain is self-contained and non-circular. The measured anisotropy decays are modeled with a spherical-top rigid-rotor treatment (Eqs. 5-9), with the mean cluster size and distribution width as fit parameters (Eqs. 10-13). The extracted sizes are then compared with the Hagena scaling laws and, for Γ* > 3000, fitted to Eq. 15 to obtain a new exponent. The cluster sizes are not constructed to reproduce the Hagena law; in fact, the paper reports systematic deviations from it (a factor of two to four for larger Ar clusters and almost an order of magnitude for Ne), which demonstrates that the comparison has independent content. The rotational temperature T_rot is taken from external literature (Ref. [46]) and the paper explicitly acknowledges that an underestimate of T_rot would mean real cluster sizes might be higher (Section IV); this is a systematic uncertainty, not a circularity. The only self-citation, Ref. [32], concerns the experimental apparatus and is not load-bearing for the size extraction or the scaling-law claim. The adjustment q_Ne = 0.9 is presented as a post-hoc empirical choice to improve agreement for neon, not as an independent prediction, so it does not constitute fitting a parameter and then calling the same data a prediction. Overall, no derivation step reduces to its own inputs by construction.

Assumptions & free parameters 6 free parameters · 8 assumptions · 0 invented entities

The absolute cluster sizes rest on a chain of literature inputs: vibrational temperatures taken as rotational temperatures (37 K Ar, 10 K Ne), log-normal width parameters (σ_Ar=1.0, σ_Ne=0.8), and a spherical-top homogeneous-sphere moment of inertia with fixed atomic radii and packing factor. The new empirical scaling parameters (a,b,q_Ne) are fitted to the same data that the model produces, so they are outputs rather than independent verifications. No new physical entities are introduced.

free parameters (6)
  • q_Ne = 0.9
    Adjusted by hand from q=0.85 so that measured Ne cluster sizes agree with the revised scaling law; no uncertainty or independent fit reported.
  • a (new Ar scaling prefactor) = 22 ± 5
    Fitted to Ar data with Γ*>3000 using Eq. 15; used in proposed new scaling regime.
  • b (new Ar scaling exponent) = 3.5 ± 0.3
    Fitted simultaneously with a to the same Ar data points; replaces b=2.35/1.64 in Hagena laws for large clusters.
  • log-normal width σ_Ar = 1.0
    Fixed based on previous broad cluster size distributions [26]; the reported mean sizes depend on this assumed distribution width.
  • log-normal width σ_Ne = 0.8
    Fixed based on prior distributions; not fitted to the present data.
  • per-trace amplitude scale = not reported
    Model contrast is scaled to the experimental contrast for each trace to account for residual elliptical polarization; affects amplitude, not dephasing time.
assumptions (8)
  • domain assumption Clusters are spherical tops with the transition dipole fixed along a figure axis; symmetric/spherical top dynamics are equivalent for parallel-parallel transitions.
    Sec. II B, Fig. 2. Needed for Eqs. 6-9. If clusters are non-spherical or the dopant does not define a stable figure axis, the anisotropy dephasing model changes.
  • domain assumption Rotational temperature equals vibrational temperature, T_rot = T_vib (37 K Ar, 10 K Ne).
    Sec. IV. Explicitly assumed; the extracted mean cluster size scales with sqrt(T_rot), so a wrong T_rot shifts all sizes.
  • domain assumption Cluster size distribution is log-normal (Eq. 11) with widths σ_Ar=1.0, σ_Ne=0.8.
    Sec. II B. Used in Eqs. 10-13; final results quoted for fixed widths.
  • domain assumption Pickup of H2Pc is proportional to geometric cross-section n^(2/3) (hard-sphere kernel), Eq. 13.
    Sec. II B. Shifts the log-normal distribution toward larger clusters; normalization constant given.
  • domain assumption Doped/undoped clusters have homogeneous-sphere moment of inertia with fcc packing factor c=0.74 and hard-sphere radii (Eq. 16).
    Supp. Info. Sec. X A. Determines B_n and hence the revival-time scaling n^{5/3} in Eq. 14.
  • domain assumption Fluorescence-lifetime averaging can be appodized to one rotational period; detection geometry treated with dipole radiation pattern.
    Supp. Info. Sec. X C. Needed for the normalization C=2.23 and contrast scaling.
  • standard math For n>=13 revivals lie beyond T_max and the discrete sum over J can be replaced by an integral (classical limit).
    Sec. II B. Numerical approximation; for smallest clusters with n<13 not valid, but experimental range mostly larger.
  • domain assumption Angular momentum transfer during doping is negligible for large clusters; evaporation of 10 Ar / 40 Ne atoms per dopant is negligible except for the smallest clusters.
    Sec. IV. For n_Hag=59 this is explicitly violated (data/model mismatch before 500 ps).

how reviews work

0 comments
Cite this review

Pith. "Pith review of Size characterization of neutral rare-gas clusters based on time-resolved polarization anisotropy measurements." pith.science (2026). https://pith.science/paper/DLSGJVSU

@misc{pith2026260723064,
  author       = {Pith},
  title        = {Pith review of: Size characterization of neutral rare-gas clusters based on time-resolved polarization anisotropy measurements},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/DLSGJVSU}},
  note         = {Machine review of arXiv:2607.23064}
}
read the original abstract

The size determination of neutral clusters is experimentally challenging. In particular, weakly-bound rare-gas clusters tend to fragment upon ionization, resulting in systematic errors in cluster size studies. In contrast, characterization of the temporal polarization anisotropy dephasing provides a soft detection scheme for cluster size estimation, which avoids fragmentation of the clusters. Here, we present a systematic experimental study of argon and neon clusters in the size range of 50 to 10.000 atoms using this technique. In order to extract the mean cluster sizes from the data, we present an efficient analytical model of the polarization anisotropy dephasing of an ensemble of doped clusters. The approach shows remarkable sensitivity to small changes in the mean cluster size of just a few tens of atoms and allows us to refine the widely used Hagena scaling law for the estimation of rare-gas cluster sizes.

Figures

Figures reproduced from arXiv: 2607.23064 by the authors.

Figure 1
Figure 1. b) molecules of which the S1←S0 transition is ex￾E ω0 𝛾~Ω |S1 |S0 TDM a) b) c) d) Detector T T z y x I∥ I⟂ e) T probe pump Ω43 Ω21 FIG. 1. Experimental scheme. a Doped rare-gas clusters. Orange arrows indicate the direction of the dopant’s transi￾tion dipole moment (TDM), black arrows the cluster rotation. b H2Pc molecule. c Relevant electronic levels of H2Pc and fluorescence yield modulated at Ω (see d and main tex… view at source ↗
Figure 2
Figure 2. FIG. 2. Relations between vectors relevant in rigid body ro ⃗ [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3. Experimental data of the temporal anisotropy dephasing for different argon (a) and neon (b) clusters sizes. [PITH_FULL_IMAGE:figures/full_fig_p006_3.png] view at source ↗
Figures from the paper (3 more)
Figure 4
Figure 4. Figure 4: FIG. 4 [PITH_FULL_IMAGE:figures/full_fig_p007_4.png]
Figure 5
Figure 5. Figure 5: FIG. 5 [PITH_FULL_IMAGE:figures/full_fig_p008_5.png]
Figure 6
Figure 6. Figure 6: FIG. 6 [PITH_FULL_IMAGE:figures/full_fig_p011_6.png]

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

52 extracted references · 8 canonical work pages

  1. [46]

    Farges, M

    J. Farges, M. F. de Feraudy, B. Raoult, and G. Torchet, Structure and temperature of rare gas clusters in a su- personic expansion, Surf. Sci.106, 95 (1980)

  2. [1]

    Mestdagh, M

    J. Mestdagh, M. Gaveau, C. Gee, O. Sublemontier, and J. Visticot, Cluster isolated chemical reactions, Interna- tional Reviews in Physical Chemistry16, 215 (1997), https://doi.org/10.1080/014423597230280

  3. [2]

    J. P. Toennies and A. F. Vilesov, Superfluid he- lium droplets: A uniquely cold nanomatrix for molecules and molecular complexes, Angewandte Chemie International Edition43, 2622 (2004), https://onlinelibrary.wiley.com/doi/pdf/10.1002/anie.200300611

  4. [3]

    M. Y. Choi, G. E. Douberly, T. M. Falconer, W. K. Lewis, C. M. Lindsay, J. M. Merritt, P. L. Stiles, and R. E. Miller, Infrared spectroscopy of helium nan- odroplets: novel methods for physics and chemistry, In- ternational Reviews in Physical Chemistry25, 15 (2006), https://doi.org/10.1080/01442350600625092

  5. [4]

    K¨ upper and J

    J. K¨ upper and J. M. Merritt, Spectroscopy of free radicals and radical containing entrance-channel com- plexes in superfluid helium nanodroplets, Interna- tional Reviews in Physical Chemistry26, 249 (2007), https://doi.org/10.1080/01442350601087664

  6. [5]

    Stienkemeier and K

    F. Stienkemeier and K. K. Lehmann, Spectroscopy and dynamics in helium nanodroplets, Journal of Physics B: Atomic, Molecular and Optical Physics39, R127 (2006)

  7. [6]

    Briant, J.-M

    M. Briant, J.-M. Mestdagh, M.-A. Gaveau, and L. Pois- son, Reaction dynamics within a cluster environment, Phys. Chem. Chem. Phys.24, 9807 (2022)

  8. [7]

    Lallement, J

    A. Lallement, J. Cuvellier, J. Mestdagh, P. Meynadier, P. de Pujo, O. Sublemontier, J. Visticot, J. Berlande, and X. Biquard, Reaction between (n2o, ar) binary clusters and barium atoms, Chem. Phys. Lett.189, 182 (1992)

Show all 52 references
  1. [8]

    Lallement, O

    A. Lallement, O. Sublemontier, J.-P. Visticot, A. Bell, J. Berlande, J. Cuvellier, J. Mestdagh, and P. Meynadier, Quenching of ba(2p1) by ch4 molecules within argon clus- ters, Chem. Phys. Lett.204, 440 (1993)

  2. [9]

    M¨ uller, S

    M. M¨ uller, S. Izadnia, S. M. Vlaming, t. Eisfeld, A. LaForge, and F. Stienkemeier, Cooperative lifetime reduction of single acene molecules attached to the sur- face of neon clusters, Phys. Rev. B92, 121408 (2015)

  3. [10]

    Izadnia, D

    S. Izadnia, D. W. Sch¨ onleber, A. Eisfeld, A. Ruf, A. C. LaForge, and F. Stienkemeier, Singlet fission in weakly interacting acene molecules, J. Phys. Chem. Lett.8, 2068 (2017), pMID: 28421765, https://doi.org/10.1021/acs.jpclett.7b00319

  4. [11]

    Bohlen, R

    M. Bohlen, R. Michiels, M. Michelbach, S. Fer- chane, M. Walter, A. Eisfeld, and F. Stienke- meier, Excitation dynamics in polyacene molecules on rare-gas clusters, J. Chem. Phys.156, 034305 (2022), https://pubs.aip.org/aip/jcp/article- pdf/doi/10.1063/5.0073503/16533358/03430...

  5. [12]

    F´ arn ´ ık, J

    M. F´ arn ´ ık, J. Fedor, J. Koˇ ciˇ sek, J. Lengyel, E. Pluhaˇ rov´ a, V. Poterya, and A. Pysanenko, Pickup and reactions of molecules on clusters relevant for atmospheric and in- terstellar processes, Phys. Chem. Chem. Phys.23, 3195 (2021)

  6. [13]

    B. R. Lee, P. K. Singh, Y. J. Rhee, and C. H. Nam, Spatiotemporal characteristics of high-density gas jet and absolute determination of size and density of gas clusters, Sci. Rep.10, 12973 (2020)

  7. [14]

    Pandey, S

    R. Pandey, S. Tran, J. Zhang, Y. Yao, and W. Kong, Bimodal velocity and size distri- butions of pulsed superfluid helium droplet beams, The Journal of Chemical Physics154, 134303 (2021), https://pubs.aip.org/aip/jcp/article- pdf/doi/10.1063/5.0047158/15588144/134303 1 online.pdf

  8. [15]

    Y. Yao, J. Zhang, W. M. Freund, S. Tran, and W. Kong, The scaling law of cluster sizes revisited: Clusters formed via coexpansion of a molecular and a rare gas species, Chem. Phys. Lett.813, 140312 (2023)

  9. [16]

    O. F. Hagena and W. Obert, Cluster formation in expanding supersonic jets: Effect of pressure, tem- perature, nozzle size, and test gas, J. Chem. Phys. 56, 1793 (1972), https://pubs.aip.org/aip/jcp/article- pdf/56/5/1793/18879085/1793 1 online.pdf

  10. [17]

    O. F. Hagena, Scaling laws for condensa- tion in nozzle flows, Phys. Fluids17, 894 (1974), https://pubs.aip.org/aip/pfl/article- pdf/17/5/894/12276979/894 1 online.pdf

  11. [18]

    O. F. Hagena, Nucleation and growth of clusters in ex- panding nozzle flows, Surf. Sci.106, 101 (1981)

  12. [19]

    O. F. Hagena, Cluster ion sources (in- vited), Rev. Sci. Instrum.63, 2374 (1992), https://pubs.aip.org/aip/rsi/article- pdf/63/4/2374/19324482/2374 1 online.pdf

  13. [20]

    O. F. Hagena, Condensation in free jets:Comparison of rare gases and metals, Z. Phys. D - Atoms Molec. Clusters 4, 291 (1987)

  14. [21]

    J. P. T. Alkwin Slenczka,Molecules in Superfluid He- lium Nanodroplets, 1st ed., Topics in Applied Physics (Springer Cham, 2022)

  15. [22]

    Farges, M

    J. Farges, M. F. de Feraudy, B. Raoult, and G. Torchet, Noncrystalline structure of ar- gon clusters. ii. multilayer icosahedral structure ofAr n clusters 50¡n¡750, J. Chem. Phys.84, 3491 (1986), https://pubs.aip.org/aip/jcp/article- pdf/84/6/3491/18957903/3491 1 online.pdf

  16. [23]

    Karnbach, M

    R. Karnbach, M. Joppien, J. Stapelfeldt, J. W¨ ormer, and T. M¨ oller,CLULU: An experimental setup for luminescence measurements on van der waals clus- ters with synchrotron radiation, Rev. Sci. Instrum. 64, 2838 (1993), https://pubs.aip.org/aip/rsi/article- pdf/64/10/2838/192...

  17. [24]

    Buck and R

    U. Buck and R. Krohne, Cluster size determination from diffractive he atom scattering, J. Chem. Phys. 105, 5408 (1996), https://pubs.aip.org/aip/jcp/article- pdf/105/13/5408/19275805/5408 1 online.pdf

  18. [25]

    Buck and H

    U. Buck and H. Meyer, Electron bombard- ment fragmentation of ar van der waals clus- ters by scattering analysis, J. Chem. Phys.84, 4854 (1986), https://pubs.aip.org/aip/jcp/article- pdf/84/9/4854/18958653/4854 1 online.pdf

  19. [26]

    Sch¨ utte and U

    S. Sch¨ utte and U. Buck, Strong fragmentation of large rare gas clusters by high energy electron impact, Int. J. Mass Spectrom.220, 183 (2002), van der Waals Clusters and Their Ions

  20. [27]

    A. B. Myers and R. M. Hochstrasser, Time-resolved flu- orescence polarization and four-wave mixing from an en- semble of free symmetric rotors, The Journal of Chemical Physics85, 6301 (1986)

  21. [28]

    P. M. Felker and A. H. Zewail, Purely rotational coher- ence effect and time-resolved sub-doppler spectroscopy of large molecules.I.Theoretical, J. Chem. Phys. 86, 2460 (1987), https://pubs.aip.org/aip/jcp/article- 13 pdf/86/5/2460/18963568/2460 1 online.pdf

  22. [29]

    J. S. Baskin, P. M. Felker, and A. H. Zewail, Purely rotational coherence effect and time-resolved sub- doppler spectroscopy of large molecules. ii. ex- perimental, The Journal of Chemical Physics86, 2483 (1987), https://pubs.aip.org/aip/jcp/article- pdf/86/5/2483/18963453/248...

  23. [30]

    J. S. Baskin and A. H. Zewail, Femtosecond real-time probing of reactions. 15. time-dependent coherent align- ment, J. Phys. Chem.98, 3337 (1994)

  24. [31]

    Awali, J.-M

    S. Awali, J.-M. Mestdagh, M.-A. Gaveau, M. Bri- ant, B. Soep, V. Mazet, and L. Poisson, Time- ResolvedObservation of theSolvationDynamics of aRydbergExcitedMoleculeDeposited on anArgon Cluster.II.DABCOatLongTimeDelays, J. Phys. Chem. A125, 4341 (2021), pMID: 34003648, https://...

  25. [32]

    Bruder, U

    L. Bruder, U. Bangert, M. Binz, D. Uhl, and F. Stienke- meier, Coherent multidimensional spectroscopy in the gas phase, J. Phys. B52, 183501 (2019)

  26. [33]

    E. J. Brown, I. Pastirk, and M. Dantus, Ultrafast ro- tational anisotropy measurements: unidirectional detec- tion, J. Phys. Chem. A103, 2912 (1999)

  27. [34]

    Herzberg,Molecular Spectra and Molecular Structure

    G. Herzberg,Molecular Spectra and Molecular Structure. II. Infrared and Raman Spectra of Polyatomic Molecules (D. Van Nostrand Company, Princeton, New York, 1945)

  28. [35]

    J. R. Taylor,Classical Mechanics, nachdr. ed. (University Science Books, Sausalito, Calif, 2005)

  29. [36]

    Goldstein, C

    H. Goldstein, C. P. Poole, and J. L. Safko,Classical Me- chanics, 3rd ed. (Addison Wesley, San Francisco Munich, 2008)

  30. [37]

    Note that if we were to treat clusters as symmetric or asymmetric tops, then we would not be able identify the transition dipole axis with the figure axis, since the chro- mophore can attach to an arbitrary spot on the cluster

  31. [38]

    Wang, R.-B

    C.-R. Wang, R.-B. Huang, Z.-Y. Liu, and L.-S. Zheng, Lognormal size distributions of elemental clusters, Chem- ical Physics Letters227, 103 (1994)

  32. [39]

    Lewerenz, B

    M. Lewerenz, B. Schilling, and J. P. Toennies, A new scattering deflection method for determining and select- ing the sizes of large liquid clusters of 4He, Chemical Physics Letters206, 381 (1993)

  33. [40]

    R. A. Aziz, A highly accurate interatomic potential for argon, The Journal of Chemical Physics99, 4518 (1993)

  34. [41]

    F. Y. NAUMKIN and D. J. W ALES, Rydberg excitations in rare gas clusters: Structure and electronic spectra of Ar* n (3≤n≤25), Molecular Physics96, 1295 (1999)

  35. [42]

    Bergersen, M

    H. Bergersen, M. Abu-samha, J. Harnes, O. Bj¨ orneholm, S. Svensson, L. J. Sæthre, and K. J. Børve, Size of neu- tral argon clusters from core-level photoelectron spec- troscopy, Physical Chemistry Chemical Physics8, 1891 (2006)

  36. [43]

    Frigo and S

    M. Frigo and S. Johnson, The Design and Implementa- tion of FFTW3, Proceedings of the IEEE93, 216 (2005)

  37. [44]

    C. R. Harris, K. J. Millman, S. J. van der Walt, R. Gom- mers, P. Virtanen, D. Cournapeau, E. Wieser, J. Tay- lor, S. Berg, N. J. Smith, R. Kern, M. Picus, S. Hoyer, M. H. van Kerkwijk, M. Brett, A. Haldane, J. F. del R ´ ıo, M. Wiebe, P. Peterson, P. G´ erard-Marchant, K. She...

  38. [45]

    Virtanen, R

    P. Virtanen, R. Gommers, T. E. Oliphant, M. Haber- land, T. Reddy, D. Cournapeau, E. Burovski, P. Pe- terson, W. Weckesser, J. Bright, S. J. van der Walt, M. Brett, J. Wilson, K. J. Millman, N. Mayorov, A. R. J. Nelson, E. Jones, R. Kern, E. Larson, C. J. Carey, ˙I. Po- lat, Y...

  39. [47]

    W¨ ormer, V

    J. W¨ ormer, V. Guzielski, J. Stapelfeldt, and T. M¨ oller, Fluorescence excitation spectroscopy of xenon clusters in theVUV, Chem. Phys. Lett.159, 321 (1989)

  40. [48]

    A. H. M. Habets,Supersonic expansion of argon into vacuum, Ph.D. thesis, Technische Hogeschool Eindhoven, Eindhoven, Netherlands (1977)

  41. [49]

    Pauly,Atom,Molecule, andClusterBeams I, 1st ed., Springer Series on Atomic, Optical, and Plasma Physics 28 (Springer, 2000)

    H. Pauly,Atom,Molecule, andClusterBeams I, 1st ed., Springer Series on Atomic, Optical, and Plasma Physics 28 (Springer, 2000)

  42. [50]

    J. R. Lakowicz,Principles ofFluorescenceSpectroscopy, 3rd ed. (Springer, 2006) pp. 353–382

  43. [51]

    Valeur and M

    B. Valeur and M. N. Berberan-Santos,Molecular Fluorescence:Principles andApplications, 2nd ed. (Wiley-VCH, 2012) pp. 181–212

  44. [2717]

    rotational

    This work is also based upon the work of COST Action CA21101 ”Confined molecular systems: from a new generation of materials to the stars” (COSY) sup- ported by COST (European Cooperation in Science and Technology). VII. ACKNOWLEDGMENT We acknowledge fruitful discussions with ...

Pith tools

Reviewed August 1, 2026 · model on record in the stance chip above.