Relativistic Density Functional Study on Uranium(IV) and Thorium(IV) Oxide Clusters of Zonohedral Geometry
Bibliographic record
Abstract
Free and ligated oxide clusters of thorium(IV) and uranium(IV) were studied with density functional theory using all-electron scalar relativistic method, as well as energy-consistent relativistic f-in-core pseudopotentials. The main driving force for the cluster formation is the sintering of the dioxoactinide moieties, which is more favorable for thorium(IV) than for uranium(IV) because, for the latter, a penalty for bending of the uranyl(IV) is to be paid. We assumed that the rhombic structural motif that exists already in the (AnO(2))(2) dimer could be a guide to explaining the preference for the existing An(6)O(8)-type clusters. On the basis of this, we have theoretically explored the possibility of the existence of similar (zonohedric) polyhedral actinide oxide clusters and found that the next possible cluster would be of An(12)O(20) stoicheometry. We have predicted by our DFT computations that the corresponding zonohedral clusters would be minima on the potential energy surface. The alternating An-O rhombic structural motif also offers a possible explanation of the existence and stoichiometry of the only nonfluorite cluster thus far, the An(12)O(20), which is nonzonohedral, nonconvex, but still a rhombic polyhedron. Our relativistic all electron DFT computations of both free cationic and ligated clusters predict that preparation of the larger clusters is not forbidden thermodynamically. We have also found that for the uranium(IV), oxide dimer and hexamer clusters are antiferromagnetic, broken spin singlet in their ground state, while ligated [U(6)O(8)] clusters prefer an all high-spin electronic configuration.
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 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 | 0.000 |
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 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".