The role of spin state on the local atomic and electronic structures of some metalloporphyrin complexes
Bibliographic record
Abstract
The Porphyrin molecule is an archetypal metalloorganic complex, which shows up in many biochemical molecules like chlorophyll, haemoglobin and cytochrome. The prospect of switching the spin in the metalloporphyrin ring is a particularly interesting one, as this could be used, for example, for spin-dependent electric transport through biomolecular devices. These molecules can be used in various applications like optical switches, information storage and non linear optics. Here, we study the molecular spin state of chloro-hemin, hemin cyanide and hemin carbonyl molecules by ADF code. Chloro-hemin has been studied by analyzing the Fe K-edge X-Ray Absorption Near Edge Structure (XANES) spectra. At first stage of investigation we assume an approximate initial geometry, then we perform the geometry optimization with different molecular spin states and search for configuration with minimal total energy with the use of Density Functional Theory (ADF 2008). The results of geometry optimization of chloro-hemin molecule performed with the GGA OPBE functional showed that configuration with total spin S = 5/2 has minimal total energy. This configuration corresponds well with the geometry structure obtained via X-Ray diffraction method (Fe-N-N angle is 13.3°). The similar calculations that were carried out for hemin carbonyl and hemin cyanide molecules showed that for these structures minimal energy is found to be for S = 1/2. The experimental Fe K-XANES spectra of the investigated compound have been collected. The theoretical analysis of the experimental data has been performed on the basis of finite difference method (FDMnes2007 program code).
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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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 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".