From structure topology to chemical composition. XXV: new insights into the close packing of cations in the structures of the seidozerite-supergroup TS-block minerals
Bibliographic record
Abstract
Abstract The titanium-silicate (TS) block is the main structural unit in the 45 seidozerite-supergroup minerals; it consists of a central O (O=Octahedral) sheet and two adjacent H (H=Heteropolyhedral) sheets where Si2O7 groups occur in the H sheets. The three HOH sheets of the TS block form a three-layered close packing of cations with an ABC repeat; mean cation–cation distances are 3.41 Å. Minerals of the seidozerite supergroup are divided into four groups based on the content of Ti and topology and stereochemistry of the TS block: in rinkite, bafertisite, lamprophyllite and murmanite groups, Ti (+Nb+Zr+Fe3++Mg+Mn)=1, 2, 3 and 4 apfu, respectively. All TS-block structures consist either solely of TS blocks or of two types of block: the TS block and an I (intermediate) block that comprises atoms between two TS blocks. The TS block propagates close packing of cations into the I block. There are two types of close-packed layers of cations in the I block: (I) a layer of Na+ and P5+ with mean cation–cation distances of 3.41 Å and (II) a layer of Ba2+ (+K+, Sr2+ and Na+) with mean cation–cation distances of 4.73 Å. The general topology of the TS block is independent of the topology and chemical composition of the I block. However direct interaction between TS and I blocks takes place in the crystal structures of jinshajiangite, bobshannonite, bafertisite, hejtmanite, delindeite and cámaraite. Interaction of Ba atoms in the I block and F (+O) atoms of the TS block results in doubling of the minimal translations, 2t 1 and 2t 2, and a concomitant change in symmetry of the structure from primitive to C-centered.
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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 | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| 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".