Trends in hyperfine coupling constants and electron‐spin <i>g</i> factors for X\documentclass{article}\pagestyle{empty}\begin{document}$^{2}\Sigma^{+}_{(g,u)}$\end{document} diatomics with 1,3, and 5 valence electrons
Bibliographic record
Abstract
Abstract A comparison of electron spin resonance (ESR) parameters calculated for X 2 Σ ( g , u ) + diatomic radicals is presented, including Li 2 + , LiK + with one valence electron (VE); Li 2 − , LiK − , LiBe, LiCa, LiB + , LiGa + , Be 2 + , and BeCa + with 3 VEs; and B 2 + , BGa + with 5 VEs. The A iso and A dip constants are studied using 6‐311+G(2df) basis sets and several methods (UHF, CISD, MP2, B3LYP, PW91PW91). For the s ‐rich radicals with 1 and 3 VEs, it is found that A iso ≫ A dip ≈0, whereas for those of p σ ‐type (such as LiB + /LiGa + with 3 VEs, and all present 5 VE radicals), the values of A iso and A dip are generally similar. The electron‐spin g factors are calculated using perturbation expansions up to second order, a Hamiltonian based on Breit–Pauli theory, and correlated (MRCI) wave functions. All radicals have negative values of Δ g ∥ and Δ g ⊥ . The sum‐over‐states expansions for Δ g ⊥ are dominated by the coupling with just one or two 2 Π excited states. The Δ g ⊥ 's of the first‐row radicals Li 2 + , Li 2 − , Be 2 + , LiBe, LiB + , and B 2 + are about −60, −5, −120, −215, −3290, and −1300 ppm, respectively, while for the mixed first/third‐row counterparts LiK + , LiK − , BeCa + , LiCa, LiGa + , and BGa + they are about −1200, −2480, −1000, −7840, −93700, and −800 ppm, respectively. These results show the strong influence heavier atoms with larger spin‐orbit constants have on g ⊥ shifts. The smaller Δ g ⊥ of BGa + (when compared with B 2 + ) is caused by the 3σ→1π and 3σ→2π excited states contributing positively and negatively, respectively, to this shift. Such positive contribution is at variance with the rule stating that an excitation of type σ→π (SOMO→virtual MO) should contribute negatively. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
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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) | 0.000 | 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".