Theoretical study of the stability of Be<sub><i>p</i></sub>@Rb<sub><i>q</i></sub> core-shell clusters
Bibliographic record
Abstract
Core-shell structures Ap@Bq can be energetically favored in bimetallic clusters when B has a lower surface energy than A, and p and q are chosen such that a single and complete outer shell of q atoms of B can form around the Ap core. If the difference in the electronegativities of A and B is large, one expects significant charge separation between the A core and the B shell. The combination of a closed atomic shell of B atoms and surface charges (core-shell charge separation) should impart stability on this type of Ap@Bq clusters. We report results of density functional theory calculations, including global optimization of cluster geometries, to characterize the prototype system BepRbq. Our calculations show that BepRbq clusters indeed adopt core-shell structures. However, they do not have particularly large surface charges and are unstable against coalescence. Surprisingly, the Rbq outer shell carries a net negative charge. This can be interpreted as the analog, for clusters, of electron spill-out at semi-infinite jellium surfaces, and it probably results from the electrons’ kinetic pressure.
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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".