Thermodynamic Properties of Gaseous Selenium Species of Atmospheric Interest
Bibliographic record
Abstract
High Resolution Image Download MS PowerPoint Slide Selenium (Se) is an essential element for fauna, flora, and human health. Up to a third of Se can cycle through the atmosphere. The volatile organic Se species include dimethyl selenide (CH 3 SeCH 3 ), dimethyl diselenide (CH 3 SeSeCH 3 ), and methaneselenol (CH 3 SeH), and will undergo rapid atmospheric oxidation. To better constrain the fate of atmospheric Se compounds, high-level ab initio electronic structure calculations were performed to estimate the thermodynamic properties of 11 gaseous Se species (HSe •, H 2 Se, CH 2 Se, CH 3 SeH, • CH 2 SeH, CH 3 Se •, CH 3 SeSe •, CH 3 SeCH 3, CH 3 Se • CH 2, CH 3 SeSeCH 3, and CH 3 SeSe • CH 2 ) using their atomization reactions. Several corrections were applied to provide highly accurate calculated standard enthalpies of formation at 298 K, Δ f H° 298 K . Standard molar entropy at 298 K, S ° 298 K, and heat capacity, C p ( T ) over the temperature range 300–1500 K, from vibrational, translational, and external rotation contributions were computed using statistical thermodynamics based on the vibrational frequencies and structures obtained at the CCSD(T)/aVTZ level of theory. Hindered rotational contributions to S ° 298 K and C p (T) were calculated from the energy levels, where the internal rotation potential was calculated at the MP2/aVTZ level of theory. The bond dissociation energies at 298 K for H–Se, Se–Se, and C–Se bonds in the Se molecules were derived from their calculated Δ f H° 298 K values. The same protocol was applied to O and S species for comparison with Se. Their Δ f H° 298 K, S ° 298 K, and C p (T) values were in good agreement with the corresponding available literature data. This work provided the first thermodynamic properties for the organic Se species. The data obtained in this work could be used in chemical-transport models to assess the fate of atmospheric Se and its speciation unravelling the Se biogeochemical cycles.
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.
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 | 0.001 | 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".