Angle-resolved electron energy loss spectroscopy of valence-shell and Si 2p pre-edge excitation of SiF4: Bethe surface and absolute generalized oscillator strength measurement
Bibliographic record
Abstract
Absolute generalized oscillator strengths (GOSs) of discrete transitions in the preionization-edge region of the valence and Si 2p inner shells of SiF4 have been determined as functions of energy loss and momentum transfer by using angle-resolved electron energy loss spectroscopy at 2.5 keV impact energy. The GOS profiles of the pre-edge features are generally consistent with the spectral assignments based on the term values of the virtual and Rydberg states from earlier valence and inner-shell studies. In particular, the GOS profiles for these low-lying preionization-edge features in the valence shell are found to be dominated by a strong maximum at zero momentum transfer, consistent with the proposed assignment of predominantly dipole-allowed Rydberg and mixed valence-Rydberg transitions. In the case of the lowest-lying preionization-edge 1t1→6a1 feature, which is formally dipole-forbidden, the present work shows that such a shape for the GOS profile is, however, not exclusive to just dipole-allowed transitions. In the Si 2p shell, the GOS profiles for the well resolved, intense σ* resonance and three higher-lying Si 2p pre-edge features have been determined and are found to be largely dominated by dipole-allowed (Rydberg) excitations. Differences in and between the GOS profiles for the valence-shell and Si 2p pre-edge features in SiF4 are identified. No discernible secondary extrema can be found in any of these GOS profiles. The present GOS results for SiF4 are compared with those reported for other cage-like molecules, including CF4 and SF6.
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.
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 | 0.001 | 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) | 0.002 | 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".