High-resolution infrared spectra of carbonyl sulfide solvated with helium atoms
Bibliographic record
Abstract
Infrared spectra of HeN–OCS clusters with N up to about 20 have been studied in the 2062 cm−1 region of the O–C stretching vibration using a tunable diode laser spectrometer to probe pulsed supersonic expansions from moderately high-pressure (<35 atm) cooled (>−60 °C) jet sources. Resolved rotation-vibration transitions have been assigned for the clusters with N=2–8, and these assignments have been confirmed in detail by observations of the corresponding pure rotational transitions in the microwave region. The vibrational frequencies (band origins) were observed to move to higher frequencies (blueshift) for N=2–5, continuing the shift previously observed for the binary complex, He–OCS. Then, for N=6–8, the vibrational frequency moves back in the direction of lower frequencies (redshift), leading towards the limiting redshift previously observed in larger helium nanodroplets with N≈103–104. These vibrational shifts are consistent with a model in which the first five helium atoms fill a “ring” around the “equator” of the OCS molecule, with the subsequent heliums then taking positions closer to the ends. The cluster rotational constants decrease monotonically (increasing rotational moments of inertia) for N=1–8, falling below the value previously observed for the “free” rotation of OCS in helium nanodroplets. Strong, sharp spectral lines from clusters in the size range N≈9–20 were also observed, but not assigned. This difficulty in extending the analysis for N>8 may be related to the onset of partially free internal rotation of the OCS within the helium cluster, which in turn has interesting implications for the nature of superfluid-type behavior in this finite scale system.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".