Abstract:
Ultracold rotational deexcitation cross sections and rate coefficients have been computed for CO collision
with proton using close-coupling method on the two-dimensional ground state potential energy surface
computed at the MRCI/cc-pVTZ level of theory. State-to-state rate coefficients have been obtained for
temperature range from 10
5
K to 200 K. The system displays higher propensity with
j
0
= 0 cross section
magnitude closer to
j
0
= 1 state, and
j
0
= 2 cross section closer to
j
0
= 3 state, from initial
j
= 4 state. In
ultracold region, the magnitude of cross section increases with the decrease in collision energy following
Wigner’s threshold law.
