Transition state dynamics and a QM/MM model for the Cl<sup></sup> + C<sub>2</sub>H<sub>5</sub>Cl S<sub>N</sub>2 reaction
Bibliographic record
Abstract
A MP2/6-31G* direct dynamics simulation is used to study the dynamics of the central barrier [Cl-C2H5-Cl] for the Cl + C2H5 SN2 reaction. The majority of the trajectories move off the central barrier to form the ClC2H5Cl complex and appear to undergo efficient IVR as assumed by RRKM theory. However, some of the trajectories move directly to products without forming the complex, a non-RRKM result. A hydrogen atom link-atom QM/MM model is described for studying the dynamics of [X-CH2R-Y] central barriers with the -R substituent. The model is used to calculate vibrational frequencies for the [Cl-C2H5-Cl] central barrier.Key words: SN2 reaction dynamics, RRKM theory, QM/MM model, central barrier dynamics, direct dynamics classical trajectories.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 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".