New Infrared Spectra of the Water–CO<sub>2</sub> Complex: Determination of Four Intermolecular Modes and Test of a High-Level Potential Energy Surface
Bibliographic record
Abstract
High resolution infrared spectra of water-CO 2 dimers are further studied using tunable infrared sources to probe a pulsed slit jet supersonic expansion. The relatively weak transition of D 2 O–CO 2 in the D 2 O ν 1 fundamental region (≈2760 cm –1 ) is observed for the first time, as are various spectra of D 2 O– 13 CO 2 . Combination bands involving the intermolecular in plane geared bend (disrotatory) mode are observed for H 2 O–CO 2 (≈1642, 2397 cm –1 ) in the H 2 O ν 2 and CO 2 ν 3 regions, for HDO–CO 2 (≈2761 cm –1 ) in the HDO ν 3 region, and for D 2 O–CO 2 (≈2386, 2705 and 2821 cm –1 ) in the CO 2 ν 3, D 2 O ν 1, and D 2 O ν 3 regions. A combination band involving the intermolecular in plane antigeared bend (conrotatory) mode is observed for D 2 O– 13 CO 2 (≈2425 cm –1 ) in the CO 2 ν 3 region. And finally, a combination band involving the intermolecular twist (internal rotation) mode is observed for D 2 O–CO 2 (≈2874 cm –1 ) in the D 2 O ν 3 region. But this twist transition actually appears as two bands of similar intensity, separated by 2 cm –1, suggesting an “accidental” near-coincidence of the “real” combination state with a “dark” background state of the same symmetry. Intermolecular mode frequencies determined from the combination bands are in very good agreement with a recent theoretical calculation based on a high-level ab initio potential surface.
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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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".