We present restricted geometry (collinear and perpendicular approaches of proton) ab initio three dimensional potential energy surfaces for H + + CN system. The calculations were performed at the internally contracted multi-reference configuration interaction level of theory using Dunning's correlation consistent polarized valence triple zeta basis set. Adiabatic and quasidiabatic surfaces have been computed for the ground and the first excited electronic states. Nonadiabatic effects arising from radial coupling have been analyzed in terms of nonadiabatic coupling matrix elements and coupling potentials.
The knowledge of accurate rate coefficients for collisional excitation of molecules by the abundant chemical species like He, H
2
and H is important in modeling the conditions of interstellar medium. In the present paper, we computed the inelastic rotational cross sections and the corresponding rate coefficients of SiS molecule in its ground vibrational state in collisions with atomic hydrogen, H. We computed
ab initio
two-dimensional (rigid-rotor) potential energy surface for the H + SiS system at high accuracy for this purpose. The excitation cross sections are performed by numerically exact close-coupling quantum mechanical formalism up to collision energy of 2000 cm
−1
. The corresponding rate coefficients are obtained in the temperature range 5–300 K.
Collisional cross-sections of inelastic rotational excitations of CN in its ground electronic state (X2Σ+) by H+ scattering are studied by the exact quantum mechanical close-coupling (CC) method at very low collision energies (0–600 cm−1) relevant to interstellar atmospheres. Ab initio rigid rotor potential energy surface computed at MRCI/cc-pVTZ level of accuracy has been employed. Rate coefficients for the rotational excitations have also been calculated. The obtained results are compared with previous theoretical calculations and analyzed whether proton collisions could be significant sources for rotationally excited CN as a possible source for cosmic microwave background of about 3 K from the interstellar media.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.