Quantum dynamical study of rotational excitation of CO+ (X 2Σ+) by He collisions

The knowledge of accurate rate coefficients for collisional excitation of molecules by the abundant species like He, H-2 and H are required for modeling the atmospheric conditions of interstellar medium. The present paper aims to study the transitions in the lowest twelve rotational levels in the ground vibrational state of CO+ (X (2)Sigma(+)) by collisions with helium atoms. We computed ab initio two-dimensional potential energy surface of (2)Sigma(+)/(2)A' symmetry for the He-CO+ van der Waals complex asymptotically correlating to He(S-1) + CO + (X (2)Sigma(+)) using restricted coupled-cluster method with perturbative treatment of triples employing augmented correlation consistent polarized valence quadruple-zeta basis set. Rovibrational bound states of He-CO+ complex for total angular momentum, J = 0 have been computed. The state-to-state rotational excitation cross sections are performed by close-coupling method up to center of mass collision energy of 2000 cm(-1). The corresponding rate coefficients are obtained up to a temperature of 300 K.