The experimental determination of the torsional barrier and shape for disilane
Bibliographic record
Abstract
The torsional spectrum of disilane was recorded for the first time under high-pressure-pathlength conditions and at a spectral resolution of 0.007 cm(-1) using a Bruker IFS-120 HR Fourier transform spectrometer. The spectrum shows six distinct Q branches. The most prominent Q branch is near 130 cm(-1) which is a blend of four components of the torsional fundamental. Of the remaining five, four were assigned to the first torsional hot band (v(4)=2<--1) and one to the second torsional hot band (v(4)=3<--2). Over 350 transitions were identified. An analysis of the torsional fundamental, the first torsional hot band, and the lower state combination differences from frequencies of the vibrational bands nu(9) and nu(9)+nu(4)-nu(4) was made to characterize the torsion-rotation Hamiltonian in the ground vibrational state. The barrier height, barrier shape, and the rotational constant about the Si-Si bond were determined to be 404.344(83) cm(-1), 2.255(65) cm(-1), and 43208(28) MHz, respectively. Comparison of simulated and the experimental spectra yielded (mu||-mu(perpendicular))/mu(perpendicular)= -4(1) for the torsional dipole moments. This ratio compares well with -3.39(6) for ethane. A comparison of molecular parameters obtained here is made with those for methyl silane and ethane.
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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) | 0.000 | 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".