Probing nitrite ion dynamics in Na<scp>NO</scp><sub>2</sub> crystals by solid‐state <sup>17</sup>O <scp>NMR</scp>
Bibliographic record
Abstract
Abstract We report a solid‐state 17O (I = 5/2) NMR study of the nitrite ion dynamics in crystalline NaNO2. Variable temperature (VT) 17O NMR spectra were recorded at 3 magnetic fields, 11.7, 14.1, and 21.1 T. The VT 17O NMR data suggest that the ion in the ferroelectric phase of NaNO2 undergoes 2‐fold flip motion about the crystallographic b axis and the corresponding rotational barrier is 68 ± 5 kJ mol−1. We also obtained a 2D 17O EXSY spectrum for a stationary sample of NaNO2 at 250 K, which, in combination with 1D 17O NMR spectral analyses, allowed precise determination of the relative orientation between the 17O quadrupolar coupling and chemical shift tensors in the molecular frame of reference. The experimentally determined 17O NMR tensors for NaNO2 were in agreement with quantum chemical calculations produced by a periodic DFT code BAND.
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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 | 0.000 | 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".