J/A+A/657/A55 C3 by collision with H2 (Santander+, 2022)
Deexcitation rate coefficients of C3 by collision with H2 at low temperatures.
Santander C., Denis-Alpizar O., Cardenas C.
<Astron. Astrophys. 657, A55 (2022)>
=2022A&A...657A..55S 2022A&A...657A..55S (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics
Keywords: astrochemistry - molecular data - molecular processes - scattering -
ISM: molecules
Abstract:
An accurate analysis of the physical-chemical conditions in the
regions of the interstellar medium in which C3 is observed requires
knowing the collisional rate coefficients of this molecule with He,
H2, electrons, and H.
The main goals of this study are to present the first potential energy
surface for the C3 +H2 complex, to study the dynamics of the system,
and to report a set of rate coefficients at low temperature for the
lower rotational states of C3 with para- and ortho-H2. Methods. A
large grid of ab initio energies was computed at the explicitly
correlated coupled-cluster with single-, double-, and perturbative
triple-excitation level of theory, together with the augmented
correlation-consistent quadruple zeta basis set
(CCSD(T)-F12a/aug-cc-pVQZ). This grid of energies was fit to an
analytical function. The potential energy surface was employed in
close- coupling calculations at low collisional energies.
We present a high-level four-dimensional potential energy surface
(PES) for studying the collision of C3 with H2 . The global
minimum of the surface is found in the linear HH-CCC configuration.
Rotational deexcitation state-to-state cross sections of C3 by
collision with para- and ortho-H2 are computed. Furthermore, a
reduced two-dimensional surface is developed by averaging the surface
over the orientation of H2. The cross sections for the collision
with para-H2 using this approximation and those from the
four-dimensional PES agree excellently. Finally, a set of rotational
rate coefficients for the collision of C3 with para- and ortho-H2
at low temperatures are reported.
Description:
File table5.dat and table6.dat contains the rates coefficients for
C3 by collision with para- and ortho-H2, respectively, for a
temperatures from 5 to 50K
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table5.dat 176 55 Rotational rate coefficients of C3 by
collision with para-H2
table6.dat 176 55 Rotational rate coefficients of C3 by
collision with ortho-H2
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
7- 8 I2 ---- ji Initial rotational state
15- 16 I2 ---- jf Final rotational state
28- 36 E9.4 cm+3/mol/s 5K Collision rates for T=5K, in cm3/molecule/s
48- 56 E9.4 cm+3/mol/s 10K Collision rates for T=10K, in cm3/molecule/s
68- 76 E9.4 cm+3/mol/s 15K Collision rates for T=15K, in cm3/molecule/s
88- 96 E9.4 cm+3/mol/s 20K Collision rates for T=20K, in cm3/molecule/s
108-116 E9.4 cm+3/mol/s 25K Collision rates for T=25K, in cm3/molecule/s
128-136 E9.4 cm+3/mol/s 30K Collision rates for T=30K, in cm3/molecule/s
148-156 E9.4 cm+3/mol/s 40K Collision rates for T=40K, in cm3/molecule/s
168-176 E9.4 cm+3/mol/s 50K Collision rates for T=50K, in cm3/molecule/s
--------------------------------------------------------------------------------
History:
From Otoniel Denis-Alpizar, otoniel.denis(at)uautonoma.cl
Acknowledgements:
Support from projects CONICYT/FONDECYT/REGULAR/No. 1200732 and 1181121
is gratefully acknowledged. This research was partially supported by
the supercomputing infrastructure of the NLHPC (ECM-02). C.C.
acknowledges Center for the Development of Nanoscience and
Nanotechnology CEDENNA AFB180001
(End) Patricia Vannier [CDS] 19-Nov-2021