THE CRYSTAL STRUCTURE OF LENINGRADITE, PbCu3(VO4)2Cl2
Bibliographic record
Abstract
The crystal structure of leningradite, PbCu 3 (VO 4 ) 2 Cl 2, a mineral from the fumaroles of the Great fissure Tolbachik eruption, located in the Kamchatka Peninsula, Russia, has been solved by direct methods from single-crystal X-ray-diffraction data and refined to R 1 = 0.047 for 1235 unique reflections with | F o | ≥ 4σ F . The mineral is orthorhombic, space group Ibam , a 9.005(7), b 11.046(9), c 9.349(7) A, V 929.9(13) A 3 , Z = 4. The structure contains one symmetrically unique Pb position coordinated by four O and four Cl atoms. The V 5+ cation is tetrahedrally coordinated by four O atoms. There are two symmetrically independent Cu sites in distorted octahedral [4O + 2Cl] coordination. The structure can be described in terms of fundamental chains consisting of corner-sharing CuO 4 squares and VO 4 tetrahedra. The chains are parallel to the c axis and are linked into a three-dimensional framework with elliptical channels occupied by the Pb 2+ cations and Cl − anions.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".