Acquisition of Wideline Solid-State NMR Spectra of Quadrupolar Nuclei
Bibliographic record
Abstract
Solid-state NMR is increasingly used for the study of quadrupolar nuclei (spin > 1/2) across the periodic table. There are numerous instances where the magnitude of the quadrupolar interaction is so great that the NMR powder patterns span ranges of hundreds of kilohertz to tens of megahertz, well beyond the range of conventional wideline patterns. Such spectra, which we refer to as ultra-wideline (UW) NMR spectra, cannot be acquired using standard high-power, rectangular pulses, since the associated excitation bandwidths are often much smaller than the pattern breadths. However, it is possible to acquire high-quality UW NMR spectra utilizing a combination of frequency-stepped spectral acquisitions, CPMG echo trains, and chirped pulses. The use of probes with large detection bandwidths and high magnetic fields also greatly aid in improving spectral quality. In this article, techniques for the acquisition of UW NMR spectra are discussed, along with hardware considerations and examples of applications of UW NMR to a variety of materials.
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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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".