Lattice Energy-Minimization Calculation in the Further Investigation of XRD and NMR Studies of Zeolite Frameworks
Bibliographic record
Abstract
A knowledge of the local structure of zeolite frameworks is an important prerequisite for a detailed and quantitative understanding of e.g. catalytic processes. In the present work the sensitivity of 1D and 2D MAS NMR experiments to the local order of framework T atoms and energy-minimization calculations for the geometrical analysis of the complete zeolite framework structure are combined to provide a most detailed view of their structural properties. Correlations of the chemical shifts, δ( 29 Si), with the mean distance between Si and its neighboring Si T atoms, d̄ (Si−Si), are presented for the three materials MFI, MEL, and MTT. Excellent agreement between experimental and computational results was obtained. In the case of MFI, this most complicated structure was used to demonstrate the viability of the method. The MTT and MEL systems showed that it is possible to deduce the unique assignment of the NMR spectra from energy-minimized structures when it is not possible using the available structural data from X-ray structure analysis. Taken together, all three investigations also demonstrate that improved structural data are obtained from lattice energy minimizations compared to those from Rietveld analysis as long as the topology of the framework is known.
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How this classification was reachedexpand
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 | 0.000 | 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 teacher head, 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".