<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si78.svg" display="inline" id="d1e1366"> <mml:mi>J</mml:mi> </mml:math> couplings in the solid state from direct energy computations
Bibliographic record
Abstract
A simple method for computing J couplings from first principles is proposed, implemented, and tested. In this approach the coupling, which is just the mixed second derivative of the energy with respect to two nuclear magnetic dipoles, is evaluated non-perturbatively by computing the total energy with different fixed dipoles of various orientations, combined in a finite difference scheme. The approach is equally applicable to molecules and solids. Details of the implementation are presented, and a variety of examples in molecules and solids are provided. • The J coupling tensor is determined directly from energy calculations. • The method is implemented in a code optimized for solids. • The method scales well with system size and can use a variety of functionals. • The results are validated against experimental results and other codes.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.003 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.249 | 0.092 |
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".