Probing the Electronic Manifold of MgCl with Millimeter-Wave Spectroscopy and Theory: (3) <sup>2</sup> Σ <sup>+</sup> and (4) <sup>2</sup> Σ <sup>+</sup> States
Bibliographic record
Abstract
The millimeter/submillimeter spectrum of magnesium chloride (MgCl) has been observed in two new electronic excited states, (3) 2 Σ + and (4) 2 Σ +, using direct absorption methods. The molecule was synthesized in a mixture of Cl 2, argon, and magnesium vapor. For the (3) 2 Σ + state, multiple rotational transitions were measured in the v = 0 level for all six isotopologues ( 24 Mg 35 Cl, 24 Mg 37 Cl, 25 Mg 35 Cl, 25 Mg 37 Cl, 26 Mg 35 Cl, and 26 Mg 37 Cl), as well as up to v = 13 for 24 Mg 35 Cl. For the (4) 2 Σ + state, less intense spectra were recorded for 24 Mg 35 Cl ( v = 0–2). Equilibrium rotational parameters were determined for both states for 24 Mg 35 Cl, as well as rotational constants and 25 Mg hyperfine parameters for the other isotopologues. A perturbation was observed between rotational levels of the two states due to an avoided crossing. Computations were also carried out at the CASPT2 and MRCISD+Q levels, and the resulting bond lengths for (3) 2 Σ + and (4) 2 Σ + states agree well with the experimental values of r e = 2.536 and 2.361 Å. The computations show that the (3) 2 Σ + state has a double-well potential; however, the state behaves as a single well with unperturbed vibrational levels up to v = 13 due to nonadiabatic interactions with the (4) 2 Σ + state.
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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 | 0.001 | 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".