Hyperfine coupling constants, electron-spin g-factors and vertical spectra of the X<sup>2</sup>Σ<sup>+</sup>radicals BeH, MgH, CaH and BZ<sup>+</sup>, AlZ<sup>+</sup>, GaZ<sup>+</sup>(Z = H, Li, Na, K). A theoretical study
Bibliographic record
Abstract
Hyperfine coupling constants (hfcc), electron-spin g-factors, excitation energies (ΔE) and oscillator strengths (f-values) are calculated for the X2Σ+ (1σ22σ) radicals YH (Y = Be, Mg, Ca) and BZ+, AlZ+, GaZ+ (Z = H, Li, Na, K). Single reference ab initio and density functional theory methods are used for the hfcc's, and multireference configuration interaction wavefunctions for ΔE's, f-values and g-shifts. In XZ+ (X = B to Ga; Z = Li to K), the 2σ unpaired electron is 60–90% pσ(X), resulting in |A⊥| being one order of magnitude larger than |A‖|. The Δg⊥'s are relatively large for just 3 valence electrons, from −3300 to −6100 ppm for BZ+, −14 100 to −29 600 ppm for AlZ+, and −93 700 to −198 300 ppm for GaZ+. Such large Δg⊥(XZ+)'s relate to the strong coupling between the close-lying X2Σ+ and 12Π(2σ → 1π) states, which results from the splitting of the 2P(s2p) state of X due to its interaction with Z+. ESR spectra are not available for any of the XZ+'s. Calculation on the hydrides YH/XH+ reproduce well the experimental hfcc's and g factors, except for AlH+, which appears to be strongly perturbed in Ar matrices. Several transitions X2Σ+ → n2Σ+ and X2Σ+ → n2Π in XZ+ have large oscillator strengths, mainly caused by intramolecular charge-transfer processes X ↔ Z and atomic-like sg ↔ pu excitations.
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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 | 0.000 |
| 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) | 0.005 | 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".