Electron-induced molecular dissociation at a surface leads to reactive collisions at selected impact parameters
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Crossed molecular beams of gases have provided definitive information concerning the dynamics of chemical reactions. The results have, however, of necessity been averaged over collisions with impact parameters ranging from zero to infinity, thus obscuring the effect of this important variable. Here we employ a method through which impact parameter averaging is suppressed in a surface reaction. We aim a highly collimated reactive 'projectile' molecule along a surface at a stationary adsorbed 'target' molecule, with both the projectile and target being observed by Scanning Tunnelling Microscopy (STM). The projectile was CF2 recoiling from electron-induced bond-breaking in chemisorbed CF3 on Cu(110) at 4.6 K. The collimation of the resulting CF2 'surface-molecular-beam' restricted it to a lateral spread of ±1° as a consequence of its interaction with the Cu rows below. This collimation was modelled by molecular dynamics simulations. In the experiments the recoiling CF2 projectile was aimed, successively, at impact parameters of b = 0 and +3.6 Å at a chemisorbed second CF2, b = +1.8 Å at a chemisorbed I-atom, or b = -4.0, b = -0.4 and b = +3.2 Å at a chemisorbed vinyl radical. The pattern of reactive and non-reactive scattering was determined by STM. These collimated surface-molecular-beams have the potential to aim molecular projectiles with selected impact parameters at the many target species identifiable at a surface by STM.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| Science and technology studies | 0.001 | 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) | 0.000 | 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 it