From structure topology to chemical composition. XXIV. Revision of the crystal structure and chemical formula of vigrishinite, NaZnTi<sub>4</sub>(Si<sub>2</sub>O<sub>7</sub>)<sub>2</sub>O<sub>3</sub>(OH)(H<sub>2</sub>O)<sub>4</sub>, a seidozerite-supergroup mineral from the Lovozero alkaline massif, Kola peninsula, Russia
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.
Bibliographic record
Abstract
ABSTRACT The crystal structure of vigrishinite, ideally NaZnTi 4 (Si 2 O 7 ) 2 O 3 (OH)(H 2 O) 4 , a murmanite-group mineral of the seidozerite supergroup from the type locality, Mt. Malyi Punkaruaiv, Lovozero alkaline massif, Kola Peninsula, Russia, was refined in space group C $\bar 1$ , a = 10.530(2), b = 13.833(3), c = 11.659(2) Å, α = 94.34(3), β = 98.30(3), γ = 89.80(3)°, V = 1675.5(2.1) Å 3 and R 1 = 12.52%. Based on electron-microprobe analysis, the empirical formula calculated on 22 (O + F), with two constraints derived from structure refinement, OH + F = 1.96 pfu and H 2 O = 3.44 pfu, is: (Na 0.67 Zn 0.21 Ca 0.05 □ 1.07 ) Σ2 (Zn 0.86 □ 1.14 ) Σ2 (Zn 0.14 □ 0.36 ) Σ0.5 (Ti 2.60 Nb 0.62 Mn 0.30 ${\rm Fe}_{{\rm 0}{\rm. 23}}^{{\rm 2 +}} $ Mg 0.10 Zr 0.06 Zn 0.05 Al 0.03 Ta 0.01 ) Σ4 (Si 4.02 O 14 ) [O 2.60 (OH) 1.21 F 0.19 ] Σ4 [(H 2 O) 3.44 (OH) 0.56 ] Σ4 {Zn 0.24 P 0.03 K 0.03 Ba 0.02 } with Z = 4. It seems unlikely that constituents in the {} belong to vigrishinite itself. The crystal structure of vigrishinite is an array of TS blocks (Titanium Silicate) connected via hydrogen bonds. The TS block consists of HOH sheets (H = heteropolyhedral and O = octahedral) parallel to (001). In the O sheet, the Ti-dominant M O (1,2) sites, Na-dominant M O (3) and □-dominant M O (4) sites give ideally Na□Ti 2 pfu. In the H sheet, the Ti-dominant M H (1,2) sites, Zn-dominant A P (1) and vacant A P (2) sites give ideally Zn□Ti 2 pfu. The M H and A P (1) polyhedra and Si 2 O 7 groups constitute the H sheet. The ideal structural formula of vigrishinite of the form ${\rm A}_{\rm 2}^{P} {\rm M}_{\rm 2}^{\rm H} {\rm M}_{\rm 4}^{\rm O} $ (Si 2 O 7 ) 2 ( ${\rm X}_{\rm M}^{\rm O} $ ) 2 ( ${\rm X}_{\rm A}^{\rm O} $ ) 2 ( ${\rm X}_{{\rm M,A}}^{P} $ ) 4 is Zn□Ti 2 Na□Ti 2 (Si 2 O 7 ) 2 O 2 O(OH)(H 2 O) 4 . Vigrishinite is a Zn-bearing, Na-poor and OH-rich analogue of murmanite, ideally Na 2 Ti 2 Na 2 Ti 2 (Si 2 O 7 ) 2 O 2 O 2 (H 2 O) 4 . Murmanite and vigrishinite are related by the following substitution: H ( ${\rm Na}_{\rm 2}^{\rm +} $ ) mur + O (Na + ) mur + O (O 2– ) mur ↔ H (Zn 2+ ) vig + H (□) vig + O (□) vig + O [(OH) – ] vig . The doubling of the t 1 and t 2 translations of vigrishinite compared to those of murmanite is due to the order of Zn and □ in the H sheet and Na and □ in the O sheet of vigrishinite.
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 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 | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.004 | 0.003 |
| Meta-epidemiology (broad) | 0.005 | 0.002 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.002 | 0.004 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.005 | 0.005 |
| Research integrity | 0.004 | 0.004 |
| 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 it