Investigation of the Ne-NH3 van der Waals complex: Rotational spectrum and <i>ab initio</i> calculations
Bibliographic record
Abstract
The Ne-NH3 van der Waals complex was investigated through analysis of microwave spectra and the construction of ab initio potential energy surfaces. Rotational spectra of the ground internal rotor state of Ne-NH3 were recorded between 7 and 24 GHz using a Balle–Flygare-type Fourier transform microwave spectrometer. In total, ten isotopomers were studied, which include Ne20 and Ne22 paired with NH3, NH315, ND3, ND2H, and NDH2. The spectroscopic constants including the N14 quadrupole coupling constants were determined and used to estimate structural and dynamical details of the van der Waals complex. For each deuterium-substituted isotopomer, a tunneling splitting was observed due to the inversion of NH3 within the ground state of the complex. One of these inversion components is missing for the NH3 and NH315 containing isotopomers for spin statistical reasons. Ab initio potential energy surfaces were constructed for three different umbrella angles of NH3 within the complex to provide information about the interaction along the NH3 inversion pathway. The interaction energies were calculated using Møller–Plesset perturbation theory to fourth order. All three surfaces have minima corresponding to structures where the van der Waals bond (the line from the center of mass of NH3 to the Ne atom) lies perpendicular to the C3 axis of NH3, with the neon atom sitting between two hydrogen atoms. At this orientation, the potential well depth is 62.66 cm−1 (285.5 μhartree) at a van der Waals bond length of 3.30 Å (6.24 bohr) for the experimental equilibrium NH3 monomer geometry.
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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 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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) | 0.004 | 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".