Density functional calculations of positron annihilation lifetimes from positron bound states in atoms

Abstract

Positron annihilation from positron bound states in atomic systems has been investigated by using density functional theory. The shifts of the positron lifetime have been analysed in terms of competing influences of correlation potentials. The results suggest that inclusion of electron - positron correlation is crucial in the assignment of positron orbitals to lifetime components in density functional investigations of bound states of the positron in negative and neutral atomic systems. The eigenvalues of positron bound states consistently correspond to the positron annihilation lifetimes in our calculations.