Potassium hydrogen disilicate: A possible model compound for <sup>17</sup> O NMR spectra of hydrous silicate glasses
Bibliographic record
Abstract
Oxygen-17 magic angle spinning, non-spinning, 1H-decoupled, 1H-17O cross-polarization, and triple-quantum magic-angle spinning nuclear magnetic resonance (NMR) spectroscopy experiments were performed at two different magnetic fields on crystalline potassium hydrogen disilicate (KHSi2O5) and hydrous and anhydrous potassium tetrasilicate (K2Si4O9), sanidine (KAlSi3O8), and haplogranite (KAlSi3O8-NaAlSi3O8-SiO2) glasses. Crystalline KHSi2O5 has two bridging oxygen sites and one non-bridging oxygen site, and the NMR parameters for these two types of sites have been determined. The non-bridging oxygen (silanol) site is well-resolved and observed in a crystalline compound with an isotropic chemical shift (δiso) of 60 ppm, a quadrupolar coupling constant (CQ) of 3.5 MHz, and an asymmetry parameter (η) of 0.35. Knowledge of the non-bridging-oxygen site parameters allows for comparisons to glassy or other materials that might have silanol-type structures. A similar peak can be found in the hydrous potassium silicate spectrum but not in the hydrous potassium aluminosilicate glass spectrum.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 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".