Fourier transform spectroscopy of BaO: New ground-state constants from the A 1Σ+–X 1Σ+ chemiluminescence
Bibliographic record
Abstract
The A 1Σ+–X 1Σ+ emission spectrum of BaO excited in a Broida-type oven was revisited using a Fourier transform spectrometer. Chemiluminescence was observed from excited BaO molecules generated from the Ba+N2O reaction, and 82 vibrational bands of 138BaO were measured in the range 8900–21 000 cm−1 at a resolution of 0.04 cm−1. Vibrational levels were observed up to v″=20 of the ground state and up to v′=11 for the excited state. In addition, 72 bands from the minor isotopomers 137BaO, 136BaO, and 135BaO were detected with v″ up to 14 and v′ up to 4. Over 15 500 lines with J″ up to 119 were measured with a precision of about 0.005 cm−1, which shows that the Broida oven is an excellent source for high-resolution emission spectroscopy. Our main goal here is to obtain an optimum set of molecular constants for the ground electronic state. To avoid complications due to the well-known perturbations for vA′⩾1 of the A 1Σ+ state, our unified combined-isotopomer analysis used a novel combination of a Dunham expansion description of the ground state with independent band-constants for data involving A-state level vA′=0, while fitting to an independent term value for each observed A-state vA′⩾1 vibration–rotation level of each isotopomer. Significantly improved ground-state constants and A-state vA′=0 band constants are obtained, together with term values for some 1372 higher-v′ A-state levels.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 teacher head, 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".