CRYSTAL CHEMISTRY OF URANYL MOLYBDATES. IV. THE STRUCTURES OF M2[(UO2)6(MoO4)7(H2O)2] (M = Cs, NH4)
Bibliographic record
Abstract
Two new uranyl molybdate hydrates, M2[(UO2)6(MoO4)7(H2O)2] (M = Cs, NH4), have been synthesized using hydrothermal methods. The crystals occur as transparent yellow needles and yellow elongate plates for M = Cs and NH4, respectively. Their structures were solved by direct methods and refined on the basis of F2 for all unique data collected with MoK X-radiation and a CCD (charge-coupled device) detector. Final R1 values are 4.1 and 3.9 % for M = Cs and M = NH4, respectively, calculated for 2178 and 2969 unique observed (|Fo | ≤ 4F) reflections, respectively. The compound Cs2[(UO2)6(MoO4)7(H2O)2] is orthorhombic, space group Pbcm, a 13.990(2), b 10.808(1), c 25.671(3) Å, V 3881.6(9) Å3, Z = 4. The compound (NH4)2[(UO2)6(MoO4)7(H2O)2] is isostructural with the Cs analogue, a 13.970(1), b 10.747(1), c 25.607(2) Å, V 3844.4(6) Å3, Z = 4. The four symmetrically independent U6+ cations in M2[(UO2)6(MoO4)7(H2O)2] are part of approximately linear (UO2)2+ uranyl ions (Ur) that are further coordinated by five ligands at the equatorial positions of uranyl pentagonal bipyramids that are capped by OUr atoms. The four symmetrically identical Mo6+ cations are tetrahedrally coordinated by O atoms. The uranyl and molybdate polyhedra link by vertex sharing to form a framework, with the low-valence M cations located in voids within the framework.
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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 | 0.001 | 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".