ONE-PHOTON ANNIHILATION IN THE PS- ION AND THE ANGULAR (E-,E-) CORRELATION IN 2-ELECTRON IONS

Various properties of the Ps- ion in its bound ground (1S) state are calculated from a very accurate explicitly correlated wave function. From the expectation value for the triple delta function [delta321] = \psi(0,0,0)\2 we estimate the one-photon annihilation rate GAMMA(gamma) in the Ps- ion and show that GAMMA(gamma) much less than GAMMA3gamma much less than GAMMA2gamma. The statistical angular correlation coefficients are analyzed for the series of two-electron ions (e-e-Z+) which includes T-, D-, H-, Mu- and Ps-.