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Record W2138224744 · doi:10.1180/minmag.2009.073.5.753

From structure topology to chemical composition. X. Titanium silicates: the crystal structure and crystal chemistry of nechelyustovite, a group III Ti-disilicate mineral

2009· article· en· W2138224744 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueMineralogical Magazine · 2009
Typearticle
Languageen
FieldMaterials Science
TopicCrystal Structures and Properties
Canadian institutionsUniversity of Manitoba
Fundersnot available
KeywordsOctahedronElectron microprobeCrystallographyCrystal structureGroup (periodic table)Crystal chemistryChemistryTitaniumSilicateBlock (permutation group theory)Chemical compositionCrystal (programming language)MineralogyGeometryMathematics

Abstract

fetched live from OpenAlex

Abstract The crystal structure of nechelyustovite, ideally Na 4 Ba 2 Mn 1.5 ☐ 2.5 Ti 5 Nb(Si 2 O 7 ) 4 O 4 (OH) 3 F(H 2 O) 6 , a 5.447(1) Å, b 7.157(1) Å, c 47.259(9) Å, α 95.759(4)°, β 92.136(4)°, γ 89.978(4)°, V 1831.7(4) Å 3 , space group P , Z = 2, D calc. 3.041 g cm –3 , from Lovozero alkaline massif, Kola Peninsula, Russia, has been solved and refined to R 1 = 13.9% on the basis of 1745 unique reflections ( F o > 15σ F ). Electron microprobe analysis yielded the empirical formula (H 2 0) 6.01 , Z = 2, calculated on the basis of 42 (O + F) a.p.f.u., H 2 O and OH are calculated from structure refinement (H 2 O = 6 p.f.u.; F + OH = 4 p.f.u.). The crystal structure of nechelyustovite is a combination of a TS (titanium silicate) block and an I (intermediate) block. The TS block consists of HOH sheets (H-heteropolyhedral, O-octahedral). The TS block exhibits linkage and stereochemistry typical for Group III (Ti = 3 a.p.f.u.) of Ti-disilicate minerals: two H sheets connect to the O sheet such that two (Si 2 O 7 ) groups link to the trans edges of a Ti octahedron of the O sheet. There are two distinct TS blocks of the same topology, TS 1 and TS 2 , that differ in the cations of the O sheet, [(Na 1.5 Mn 1 ☐ 0.5 )Ti] and [(Na 2 Mn 0.5 ☐ 0.5 )Ti] (4 a.p.f.u.) respectively. The TS 1 and TS 2 blocks have two different H sheets, H 1,2 and H 3,4, where (Si 2 O 7 ) groups link to [5]- and [6]-coordinated (Ti,Nb) polyhedra respectively. There are three peripheral sites, A P (1—3), occupied mainly by Ba (less Sr and K) at 96, 86 and 26% and one peripheral site A P (4) occupied by Na at 50%. There are two I blocks: the I 1 block is a layer of Ba atoms; the I 2 block consists of H 2 O groups and A P (3) atoms. TS blocks alternate with I blocks or link through hydrogen bonds (as in epistolite). There is a sequence of four TS blocks and three I blocks per the c cell parameter: TS 2 — I 1 — TS 1 — I 2 — TS 1 — I 1 — TS 2 .

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow), Insufficient payload (model declined to judge)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.091
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0010.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0030.000

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.

Opus teacher head0.009
GPT teacher head0.225
Teacher spread0.216 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it