FAR-INFRARED AND MICROWAVE SPECTROSCOPY OF HCOOCH<sub>3</sub> II.
Bibliographic record
Abstract
The known interstellar molecule, methyl formate (HCOOCH$_3$) has been studied by microwave spectroscopy since 1959 \\footnote{R. F. Curl, \\textit{J. Chem. Phys.} \\underline{\\textbf{30}}, 1529 (1959).}. The laboratory spectra of methyl formate exhibit many unassigned transitions that are \n due to rotational transitions in the low-lying vibrational excited states. The first torsional excited state was reported in 2003 $\\footnote{H. Odashima, K. Ogata, K. Takagi, \\& S. Tsunekawa, \\textit{Molecules} \\underline{\\textbf{8}}, 139 (2003).}$, and up to the second torsional excited state was identified in laboratory and in space. \n$\\footnote{S. Takano, Y. Sakai, S. Kakimoto, M. Sasaki, \\& K. Kobayashi, \\textit{Publ. Astron. Soc. Jpn.} \\underline{\\textbf{64}}, 89 (2012).}$\n$\\footnote{K. Kobayashi, K. Takamura, Y. Sakai, S. Tsunekawa, H. Odashima, \\& N. Ohashi, \\textit{Astrophys. J. Suppl. Ser.} \\underline{\\textbf{205}}, 9 (2013) and references therein.}$ \n \nOur laboratory microwave spectra include a series of unknown $K_a$=0,1 transitions. Based on relative intensities, we estimate that these transitions arise from an excited state about 300 cm$^{-1}$ above the ground state. To facilitate identification, we have taken spectra of methyl formate in the 260-370 cm$^{-1}$ range at Far-Infrared Beamline of the Canadian Light Source synchrotron. The resolution was instrument-limited to 0.00096 cm$^{-1}$. The spectra were very dense, and included the overlapping $\\nu_{12}$ (C-O-C deformation) and $\\nu_{17}$ (C-O torsion) modes. Conventional assignment proved very difficult, so we calculated a-type $K_a$ =0, and 1 rotation-vibration spectra based on the unknown and ground-state microwave data, and gave them arbitrary origins near 300 cm$^{-1}$. By correlating them with the far-infrared spectrum, we were able to determine that the new series correspond to $\\nu_{12}$ near 312 cm$^{-1}$.$\\footnote{K. Kobayashi, Y. Sakai, M. Fujitake, D. W. Tokaryk, B. E. Billinghurst \\& N. Ohashi, \\textit{Can. J. Phys.} \\underline{\\textbf{98}}, 551 (2020).}$ We will report on our assignment technique and results, as well as any further developments we have made in extending the assignments of both the microwave and far-infrared spectra.
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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) | 0.005 | 0.001 |
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".