Electron scattering by the sulfur fluoride radical using the R-matrix method

The R-matrix method is used to study electron collisions with the molecular radical sulfur fluoride (SF). The elastic and excitation cross sections of the six lowest-lying electronically excited states of the SF radical are presented for incident electron energies up to 15 eV. These excited states have symmetries (4)Sigma(-), (2)Sigma(-), (2)Delta, (2)Sigma(+), (2)Piand (4)Pi, and vertical excitation energies in the range 3.32-9.48 eV. Configuration interaction (CI) wavefunctions are used to represent the target states. In our CI model we keep the 1sigma, 2sigma, 3sigma, 4sigma and 1Pi molecular orbitals fully occupied and the remaining 13 electrons are free to occupy the 5sigma, 6sigma, 7sigma, 8sigma, 9sigma, 2Pi and 3Pi orbitals. We detect a bound state of SF- of (1)Sigma(+) symmetry with an adiabatic electron affinity of 1.46 eV. There are two shape resonances of (3)Pi and (1)Pi symmetries centred around 1 and 2 eV respectively, with a common configuration 3Pi(3)8sigma. Our calculations also predict four core-excited shape resonances of symmetries (3)Sigma(-), (1)Sigma(-), (3)Pi and I I in the energy range 8-13 eV having configurations 3Pi(2)8sigma(2) and 2Pi(3)3Pi(4)8sigma.