Quaternary Chalcogenides La<sub>3</sub>Sn<sub>0.5</sub>InS<sub>7</sub> and La<sub>3</sub>Sn<sub>0.5</sub>InSe<sub>7</sub>
Bibliographic record
Abstract
The quaternary chalcogenides La3Sn0.5InS7 and La3Sn0.5InSe7 were prepared by reactions of the elements at 1050 °C and 950 °C, respectively. They adopt noncentrosymmetric structures [hexagonal, space group P63, Z = 2; a = 10.2993(11) Å, c = 6.0921(6) Å for La3Sn0.5InS7; a = 10.6533(7) Å, c = 6.4245(4) Å for La3Sn0.5InSe7] in which the half‐occupancy of Sn atoms within octahedral sites classifies them as belonging to the La3Mn0.5SiS7‐type branch of the large family of quaternary rare‐earth chalcogenides RE3M1–xM′Ch7. The site distribution in La3Sn0.5InCh7, with higher‐valent Sn atoms occupying octahedral instead of tetrahedral sites, is reversed from the typical situation observed in other RE3M1–xM′Ch7 compounds. The ordered distribution of Sn atoms in octahedral sites and In atoms in tetrahedral sites was evaluated by bond valence sum analyses. Moreover, 119Sn solid‐state nuclear magnetic resonance (NMR) spectroscopy confirms the occupation of Sn4+ species exclusively within octahedral sites. An optical bandgap of 1.45 eV was found for La3Sn0.5InS7. Band structure calculations on an ordered superstructure model of La3Sn0.5InS7 reveal that avoidance of strongly Sn–S antibonding levels is an important driving force for the Sn deficiency.
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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) | 0.002 | 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".