Anharmonicity Effects in the Vibrational CD Spectra of Propylene Oxide
Bibliographic record
Abstract
This study reports the first vibrational circular dichroism (VCD) spectra of propylene oxide isolated in an argon matrix. The narrow bandwidth achieved, in addition to the rich VCD features, allows a thorough analysis of the spectra and detailed comparison with the calculated harmonic and anharmonic IR and VCD spectra. Several bands in the fingerprint region are identified as nonfundamental modes based on the harmonic calculation, and three of them feature significant VCD intensity. Anharmonic VCD intensity calculations were carried out using a newly developed methodology based on the second-order level of vibrational perturbation theory. All new bands observed can be undoubtedly assigned to combination or overtone modes except the band at 1486.4 cm –1, which is tentatively identified to contain contributions from an overtone and a combination mode. The study also reveals that the current theoretical approach for anharmonic contributions to VCD spectra needs to be further improved when there is an accidental resonance involved.
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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) | 0.001 | 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".