Computer simulations of the dynamics of doubly occupied N2 clathrate hydrates
Bibliographic record
Abstract
We have studied the dynamical properties of doubly and singly occupied structure II N2 clathrate hydrates by performing a series of classical molecular dynamics calculations. The intermolecular vibrational density of states of the guest molecules show the most explicit changes when going from single to double occupancies. Instead of the narrow peak for single occupancy (at 20 cm−1), a broad range of frequencies occurs between 0 and 200 cm−1 with four modes, which have been assigned to the possible vibrations in the cage. This spectrum provides a unique fingerprint of double occupancy. For the host lattice, the libron band and the optic phonon branch show lower frequencies as compared to single fillings. In contrast, the acoustic phonon branch shifts to lower frequencies for a single filling of the large cases. We find that there is a large vibrational guest–host coupling for both single and double occupancies, although the frequency range is broader in the latter case. There is a significant translational diffusion of the N2 molecules in the doubly occupied cages. Occasionally both molecules simultaneously migrate from one local energy minimum to another. An orientational order of the N2 molecules occurs only within the small cages. However, the relative orientation of the two molecules in the doubly occupied cages is preserved in time.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 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) | 0.002 | 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".