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Collisional energy transfer in ethanimine + He system
Vivek Vijay1, Francesca Tonolo2, Ernesto Quintas-Sánchez3
1Marquette University, Milwaukee, Wisconsin, USA. Dmitri.Babikov@marquette.edu.
Physical Chemistry Chemical Physics : PCCP
|July 16, 2026
Summary
Astronomers detected prebiotic ethanimine in space, showing non-equilibrium populations. New calculations reveal energy transfer differences between its isomers, crucial for interpreting cosmic observations.
Area of Science:
- Astrochemistry
- Quantum Chemistry
- Interstellar Medium
Background:
- Ethanimine (CH3CHNH) is a prebiotic molecule found in Galactic Center molecular clouds.
- Observations show non-equilibrium rotational state populations in ethanimine isomers due to radiative and collisional processes.
- Accurate radiative transfer models require understanding state-to-state collisional transitions.
Purpose of the Study:
- To compute state-to-state cross sections for ethanimine isomers interacting with Helium.
- To investigate collisional energy transfer mechanisms in ethanimine.
Main Methods:
- Constructed accurate potential energy surfaces for ethanimine-He interaction.
- Utilized full-quantum coupled-channel and coupled-states methods.
- Employed the mixed quantum/classical theory for inelastic scattering.
Main Results:
- Identified strong propensities for transitions toward Δka = 0.
- Observed specific Δj and Δkc transition patterns.
- Found ~10% differences in energy transfer between E- and Z-ethanimine isomers.
Conclusions:
- Calculated cross sections are essential for interpreting ethanimine observations in interstellar clouds.
- The study provides insights into collisional energy transfer dynamics for prebiotic molecules.
- The mixed quantum/classical approach is useful for higher collision energy studies.
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