O(3P)+CO2 SCATTERING DYNAMICS WITH MCTDH FOR
UNDERSTANDING OXYGEN ESCAPE FROM MARS ATMOSPHERE
B.M.Krishna, Department of Physics, Khalifa University, Abu Dhabi, UAE,
(balasubramoniam.krishnan@ku.ac.ae) M. Gacesa, Space and Planetary Science Center and Department of
Physics, Khalifa University, Abu Dhabi, UAE.( marko.gacesa@ku.ac.ae)

We report cross sections for the collision of
O(3P) + CO2 scattering at collision energies which
are important to understand the O escape from Mars
atmosphere. The cross sections were calculated using
newly developed state-of-the-art ab initio potential
energy surfaces (PESs) correlating the lowest energy
asymptote of the complex.

cross-sections of O(3P)-CO2 compared to that of the
rigid rotor approximation previously reported [1].
This also allows for an understanding of rotational
and vibrational energy transfer processes in this
atom-triatom collision.
Aknowledgement: The authors are partly supported by the internal grants 8474000362-KU-FSU
(BMK,MG) and 8474000336-KU-SPSC (MG).
References:
[1] M. Gacesa, R. J. Lillis, and K. J. Zahnle,
O(3P)+CO2 scattering cross-sections at superthermal
collision energies for planetary aeronomy, MNRAS
491, 5650–5659 (2020)

Figure 1: Coordinate fpr O + CO2 collison with a
bending geometry with the <OCO angle at 120 degrees.
The work presented here explores for the first
time a fully quantum mechanical approach to providing inelastic cross-sections and rates using Multiconfigurational Time Dependent Hartree (MCTDH)
method.

Figure 2: Contour plot of the the 3A2 potential
energy surface for the O + CO2 complex.
The new PES allows us to investigate the influence
and importance of in-plane bending vibration of CO2
and the stretching vibration of CO2 to the scattering