Positron annihilation in the positronium negative ion Ps −

Abstract

The energy and other bound state properties of the positronium negative ion Ps − (or e − e + e − ) are determined to high accuracy with the use of extremely accurate variational wave functions. The determined total energy of the ground state in the Ps − ion E = − 0.26200507023298010776885 a.u. is the lowest variational value obtained for this system. The two-, three- and one-photon annihilation rates are determined with the highly accurate wave functions. We also consider the computation of the lowest order relativistic and QED corrections.