Layered single-bonded nonmolecular phase of nitrogen from first-principles simulation
Bibliographic record
Abstract
A phase of nonmolecular nitrogen, found by first-principles density functional theory simulations at high pressures is reported. The phase has a $P{2}_{1}∕m$ symmetry and consists of two-dimensional layers of fused ${\mathrm{N}}_{6}$-rings where the rings are all in the boat conformation. The phase has been designated the layered boat or LB phase. Properties of LB are presented in comparison with other computationally studied polymeric phases of nitrogen. In particular, the structure of LB is compared to two other layered phases, black-phosphorus (BF) and $\ensuremath{\alpha}$-arsenic $(A7)$. A calculated enthalpy versus pressure phase diagram reveals that LB lies between BF and $A7$ in enthalpy at pressures less than $200\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$. At pressures higher than this, the enthalpy of LB edges above that of $A7$. The metastability of LB at low pressures is probed by a few simple tests and the band structure is calculated.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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".