R-matrix calculations of electron collisions with a lithium atom at low energies

摘要

R-matrixcalculations of the electron collisions with a lithium atom at energies below the 3s excitation threshold are presented. The ~1S~e, ~3S~e, and ~1P~o phase shifts calculated in the near-threshold energy range are in excellent agreement with previous theoretical studies. The threshold behavior of the ~3P~o phase shift is accurately analyzed along with the resonance located at the scattering energy ～60 meV. The phase shifts and cross sections calculated here show two resonances below the 3s threshold that have not been previously reported.