From NQR to NMR: The complete range of quadrupole interactions
Bibliographic record
Abstract
Abstract The theoretical transition energies of a spin 3/2 under a combination of quadrupolar and Zeeman interactions are mapped out as a function of magnetic field. This allows us to follow the spectroscopy continuously from zero magnetic field (NQR, nuclear quadrupole resonance) through to high magnetic field (quadrupole‐perturbed NMR). This calculation is made possible by a theoretical approach that makes maximum use of the angular momentum properties of the spin system. In this approach, the detailed form of the spin operators are not required, only their angular momentum quantum numbers. No commutators need be evaluated, and the method is easily coded for computer calculation. Application of the Wigner‐Eckart theorem and selection rules means that there are only two nonzero reduced matrix elements that are needed for a spin 3/2, and there are explicit formulae for them. In looking at the transition energies, the crucial parameter is the orientation of the quadrupole tensor to the magnetic field. If the angle is nonzero, then the quantization of the spins must shift. At zero field, the quantization is defined by the electric field gradient tensor, which is molecule‐fixed at some arbitrary angle to the magnetic field. This direction of quantization must change as the magnetic field increases, to lie close to the z axis at high field. In the region where the two interactions are comparable, all the familiar rules break down and the response is highly nonlinear. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part A 22A: 69–78, 2004.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".