The Average Structure of a Fine-Grained Nepheline to 900 °C: Disorder of O1, Al-Si, and K-Vacancy
Bibliographic record
Abstract
A fine-grained nepheline sample from Egan Chutes, Ontario, with the chemical composition (K1.32▯0.68)(Na6.05Ca0.22)[Al7.77Si8.21O32], where ▯ represents vacancies, was studied through in situ synchrotron powder X-ray diffraction (XRD) data and Rietveld structure refinement from 26 to 900 °C on heating and cooling. The average structure was refined in the space group P63. The satellite reflections in nepheline give rise to order–disorder transitions. The average <Al,Si-O>{4} distances in nepheline indicate a partially ordered Al-Si distribution, especially in the Al2 and Si2 sites at room T before heating. The nepheline structure shows that except for the positional disorder of the O1 oxygen atom, the other atoms are well defined and contain no unusual features. Vacancies, ▯, occur at the K site. Different satellite (s) reflections arise from (1) positional order of the O1 atoms to 299 °C (s1 disappears), (2) K-▯ order to 486 °C (s2 and s3 disappear), and (3) some Al-Si order 900 °C, where some satellite reflections are present. Complete Al-Si order is obtained at room T on cooling.
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 | 0.000 |
| 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".