Die Lanthanoid(III)-Oxid-Oxoselenate(IV) <i>Ln</i> <sub>2</sub>O[SeO<sub>3</sub>]<sub>2</sub> (<i>Ln</i>=Sm–Tm)
Bibliographic record
Abstract
Abstract Single crystals of compounds with the composition Ln 2O[SeO3]2 (Ln=Sm–Tm) were synthesized by solid-state reactions of the lanthanoid sesquioxides (Ln 2O3) with the corresponding tribromides (LnBr3) and selenium dioxide (SeO2) in a molar ratio of 2:1:2 in evacuated torch-sealed silica ampoules. For the terbium case, Tb4O7 and SeO2 have been reacted with elemental Tb in a molar ratio of 3:14:2. These lanthanoid(III) oxide oxoselenates(IV) all crystallize tetragonally with the space group P42/ncm and decreasing lattice parameters from the lighter to the heavier Ln 3+ cations (from a=1077.03(8) pm and c=526.38(4) pm for Ln=Sm to a=1049.60(8) pm and c=516.04(4) pm for Ln=Tm) according to the lanthanide contraction. They show a three-dimensional network of condensed [LnO8]13− polyhedra with a channel structure, where all ψ 1-tetrahedral [SeO3]2− units are coordinating with their O2− anions to square antiprisms [LnO8]13− and pointing with their non-bonding electron pairs into the empty channels, which propagate along [001]. As another characteristic feature of the crystal structure, [OLn 4]10+ tetrahedra containing the non-selenium-bonded O2− anions are trans-edge-connected to form {[O L n 4 / 2 e ] 4 + } ∞ 1 ${}_\infty ^{\rm{1}}{\rm{\{ [O}}Ln_{4/2}^{\rm{e}}{{\rm{]}}^{{\rm{4}} + }}{\rm{\} }}$ chains, which run parallel to the lone-pair channels in [001] direction and build up a tetragonal rod-packing.
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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) | 0.001 | 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 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".