The local structure in liquid methylamine and methylamine–water mixtures
Bibliographic record
Abstract
Molecular dynamics (MD) computer simulations are carried out on liquid methylamine and on 10 and 30 wt % aqueous solutions of methylamine. The local three-dimensional structure in these liquid systems is investigated using standard one-dimensional radial distribution functions and the fully three-dimensional measure of the local structure around the molecule, spatial distribution functions. Time correlation functions for the linear and angular motion of methylamine in the molecular coordinate system are also explored. From this analysis, a detailed structural picture emerges, revealing local molecular environments in these liquids that are both complex and varied. Hydrogen bond balance is found to play a key role in determining preferred arrangements. Strong hydrogen bonds are formed around the amino group in the pure liquid and in aqueous solution. At the same time, there is a strong hydrophobic association of methyl groups. The hydration structure in aqueous solution is found to be particularly rich, where in addition to the usual H-bonding nearest neighbors in the first hydration shell of the amino group, there are bridging water molecules and a novel type of distinctly non-H-bonding neighbors. The hydration structure in aqueous methylamine solution differs substantially from that found in methanol–water liquid mixtures.
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 | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".