Radiative association of atomic and ionic carbon
Abstract
We present calculated cross sections and rate coefficients for the formation of the dicarbon cation (C2+) by the radiative association process in collisions of a C(3P) atom and a C+(2Po) ion. Molecular structure calculations for a number of low-lying doublet and quartet states of C2+ are used to obtain the potential energy surfaces and transition dipole moments coupling the states of interest, substantially increasing the available molecular data for C2+. Using a quantum-mechanical method, we explore a number of allowed transitions and determine those contributing to the radiative association process. The calculations extend the available data for this process down to the temperature of 100 K, where the rate coefficient is found to be about 2× 10-18 cm3/s. We provide analytical fits suitable for incorporation into astrochemical reaction databases.