Pressure-Induced Polymorphic Transitions in Crystalline Diborane Deduced by Comparison of Simulated and Experimental Vibrational Spectra
Bibliographic record
Abstract
We investigate and assign the pressure-induced structural transformations in crystalline diborane (B 2 H 6 ) observed spectroscopically by Song and co-workers ( J. Phys. Chem. B 2009, 113, 13509; J. Chem. Phys. 2009, 131, 174506) between 3.5 and 24 GPa at room temperature. The assignment is made by calculating the Raman and infrared vibrational spectra of 10 candidate structures at various pressures and comparing the results to experiment. We find that solid diborane undergoes a polymorphic transition at about 6 GPa from β-diborane ( P 2 1 / n ) to a P 2 1 / c diborane and possibly a second transition near 14 GPa to another P 2 1 / c diborane structure. We conclude that no cyclic oligomers or chains of the composition (BH 3 ) n ( n > 2) are formed from diborane up to at least 24 GPa under the experimental conditions employed by the Song group, even when such structures are thermodynamically favored. This suggests that pressure-induced chemical transformations of molecular crystals of diborane are kinetically hindered.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 teacher head, 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".