The formation of AlF by radiative association

Abstract

The formation of the aluminium monofluoride molecule AlF by radiative association of the Al and F atoms is estimated. The radiative association of Al(2P) and F(2P) atoms is found to be dominated by the approach along the A1Π potential energy curve accompanied by spontaneous emission into the X1Σ+ ground state of the AlF. For temperatures ranging from 300 to 14 000 K, the rate coefficients are found to vary from 1.35 × 10−17 to 9.31 × 10−16 cm3 s−1, respectively. These values indicate that only a small amount of AlF molecules can be formed by radiative association in the inner envelope of carbon-rich stars and other hostile environments.