<sup>14</sup>N Quadrupolar, <sup>14</sup>N and <sup>15</sup>N Chemical Shift, and <sup>14</sup>N−H Dipolar Tensors of Sulfamic Acid
Bibliographic record
Abstract
A 14 N solid-state NMR single crystal study was used to determine the 14 N quadrupolar, chemical shift, and 14 N− 1 H dipolar tensors of sulfamic acid. The quadrupolar tensor is nearly axially symmetric, with the quasi-unique axis aligned 3° away from the N−S bond. The quadrupole coupling constant of 0.794 MHz is substantially less than the gas-phase value (1.6682 MHz); ab initio calculations show that the difference can be attributed almost entirely to the significantly shorter N−S bond in the solid state. The single crystal study, together with 15 N CP/MAS and CP/static experiments, yields an isotropic chemical shift that lies close to its solution value, and a chemical shielding anisotropy of about −80 ppm, and the dipolar couplings are about 10% smaller than computed from the neutron structure, probably because of vibrational averaging. All three tensors are almost collinear. HF, MP2, CI, and DFT(B3LYP) calculations of the nitrogen quadrupole coupling constant and shielding are also reported.
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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".