Neptunium(VII) in high-ionic-strength alkaline solutions — [NpO <sub>2</sub> (OH) <sub>4</sub> ] <sup>1–</sup> or [NpO <sub>4</sub> (OH) <sub>2</sub> ] <sup>3–</sup> ?
Bibliographic record
Abstract
Relativistic density functional theory (ZORA-PBE, COSMO solvation) is used to address the title question, based on comparison with recent experimental data ( 1 ). Structural data (bond lengths), vibrational frequencies, and 17 O NMR chemical shifts are used to prove that [NpO 4 (OH) 2 ] 3– is the predominant species in high-ionic-strength alkaline solutions of Np VII . Neptunium(VII) complexes have stronger bonds than their formally isoelectronic uranium(VI) analogues. The experimentally observed 300 ppm shift in 17 O chemical shifts between the known [UO 2 (OH) 4 ] 2– and Np VII solution is shown to be partly a function of the central metal (Np VII vs. U VI ) and not of the coordination environment (tetraoxo vs. dioxo). Comparing, for a given An (U VI or Np VII ), actinyl complexes [AnO 2 X 4 ] 2–/1– , X = Cl, F, OH, a decreasing strength of the axial actinyl bond is observed that is traced to electronic factors (equatorial π-competition).
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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 | 0.000 |
| 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 | 0.000 |
| 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 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".