Overtone-Induced Reactions on the HO<sub>2</sub>NO<sub>2</sub>Potential Surface
Bibliographic record
Abstract
We report density-functional theory calculations performed at the B3LYP/6-311++G(3df,3pd) level on the lowest energy singlet and triplet potential energy surfaces of the HO 2 NO 2 system. The reaction forming HONO + ground-state oxygen, O 2 ( 3 Σ), from HO 2 + NO 2 proceeds via a triplet transition state which lies about 2 kcal/mol above reagents, and about 22 kcal/mol above ground-state HO 2 NO 2 . Dissociation of ground-state pernitric acid into HO 2 + NO 2 is energetically accessible through excitation of the v = 2 overtone level of the OH stretching vibration (v OH = 2). Overtone excitation into v OH ≥ 3, followed by a singlet−triplet potential surface crossing, could lead to HONO + O 2 ( 3 Σ) products. On the singlet potential surface, the energetic barrier to the reaction forming HONO + O 2 ( 1 Σ) lies very near the product energy. This product channel may be accessible via excitation of the v OH = 3 or 4 overtones. Complexation with a single water molecule does not alter the barrier height to reaction, but may promote reaction by changing the strength and or location of the singlet−triplet coupling. The reaction of HONO (v OH ≥ 3) with O 2 ( 3 Σ) may form HO 2 + NO 2 in polluted urban atmospheres with a rate several orders of magnitude smaller than that of HONO photolysis.
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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 | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".