Structure and charge density distribution of amine azide based hypergolic propellant molecules: a theoretical study
Bibliographic record
Abstract
A quantum chemical calculation and charge density analysis of some amine azide based propellants (DMAZ, DMAEH, ADMCPA, AMCBA and ACPA) have been carried out to understand the geometry, bond topological, electrostatic, and energetic properties. The topological properties of electron density of the molecules were determined using Bader’s theory of atoms in molecules from the wave functions obtained from the density functional method (B3LYP) with the 6-311G** basis set. The electron density distribution of these molecules reveals the nature of chemical bonding in the molecules. The azide group attached C−N bonds of all molecules exhibit the electron density of ρ bcp (r) ∼1.639 e Å −3 and the Laplacian of electron density ∇ 2 ρ bcp (r) is ∼–14.0 e Å −5 , in which the corresponding values of the ADMCPA molecule are relatively high, 1.725 e Å –3 and –15.2 e Å −5 respectively, whereas for the methylamine group attached C–N bonds, these values are found to be higher (1.824 e Å –3 and –17.25 e Å −5 ). The Laplacian of terminal N–N bonds of the azide group is highly negative, indicating that these charges are highly concentrated, whereas the charge concentration of the dimethylamine group attached N–N bond of DMEAH is very much less, confirming that the bond is the weakest bond among the molecules. The energy density has been calculated for each bond of the molecules, which insights the energy density distribution of the molecules. Relatively, the molecules exhibit distinct electrostatic properties that are related to different charge distribution in the molecules. Large negative electrostatic potential regions are found at the vicinity of the amine and azide groups of the molecules. The charge imbalance parameter of the molecules has been determined and shows that the DMAEH molecule is the least sensitive molecule in this series.
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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) | 0.000 | 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".