Precision Lamb-dip infrared spectra of the C–N stretching band of CH3NH2 with a CO2-laser/microwave-sideband spectrometer
Bibliographic record
Abstract
We report saturation dip spectroscopy in the C-N stretching band of CH(3)NH(2) with a resolution of 0.4 MHz and an accuracy of 0.1 MHz by use of a CO(2)-laser/microwave-sideband spectrometer. The wide tunability, Lamb-dip resolution, absolute frequency accuracy, and high sensitivity of our dual-mode instrument were all key features in making precise measurements for a range of lines in the densely crowded spectrum with its complex pattern of splittings arising from the large-amplitude CH(3) torsion and NH(2) inversion. We focused on achieving resolution and assignment of transitions within the highly blended Q branch of the C-N stretch and on observations of the important K=0 sequences of Aa and Ea torsion-inversion symmetry. Term values of the latter were fitted to J(J+1) power-series expansions to obtain the K=0 C-N stretching effective B values and substate origins, from which calculated ground-state substate energies were subtracted to yield values of 1044.7061 and 1044.8011 cm(-1) for the Aa and Ea subband origins, respectively. We thereby estimate a mean value of 1044.75(5) cm(-1) for the vibrational band origin and 0.7323(5) cm(-1) for the effective upper-state B value for the C-N stretching fundamental of CH(3)NH(2).
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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) | 0.000 | 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".