THE CRYSTAL STRUCTURES OF X(NpO2)(PO4)(H2O)3 (X = K+, Na+, Rb+, NH4+) AND THEIR RELATIONSHIP TO THE AUTUNITE GROUP
Bibliographic record
Abstract
Four Np 6+ phosphates with compositions X (NpO 2 )(PO 4 )(H 2 O) 3 , X = K + , Na + , Rb + , NH 4 + , have been synthesized by mild hydrothermal methods, and their structures have been determined. Single-crystal X-ray-diffraction data were collected using Mo K α radiation and an APEX CCD detector. The Np 6+ structures containing K + , Na + , Rb + , and NH 4 + ( KP1 , NaP1 , RbP1 , NH 4 P1 ) were refined to agreement indices R 1 0.042, 0.051, 0.066, and 0.023 calculated for 831, 856, 798, and 857 unique observed reflections, respectively. KP1 crystallizes in space group P 4/ ncc , with a 6.9564(8), c 17.826(4) A, V 862.6(2) A 3 , Z = 4. NaP1 also is tetragonal, P 4/ ncc , with a 7.005(1), c 16.986(4) A, V 833.6(3) A 3 , Z = 4. RbP1 is tetragonal, P 4/ ncc , with a 7.031(4), c 17.87(2) A, V 884(1) A 3 , Z = 4. NH 4 P1 crystallizes in space group P 4/ ncc with a 6.9843(6), c 18.023(3) A, V 879.2(2) A 3 , Z = 4. Each of these structures contains sheets of composition [(NpO 2 )(PO 4 )] − consisting of Np 6+ in square bipyramidal coordination and phosphate tetrahedra. These sheets are topologically identical to the well-known uranyl phosphate sheets of the autunite group. The monovalent cations and H 2 O group are located in the interlayer, where they balance the charge on the sheets and provide linkages between the sheets.
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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 | 0.001 | 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 | 0.002 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".