The multireference configuration interaction method is applied with extrapolations to atomic systems containing two positrons, Ps(2)H(+), Ps(2)F(+), and Ps(2)CI(+). The stability of these systems is examined. These systems are all stable against the lowest dissociation channel e(+) + PsX. The dissociation energies to the e(+) + PsX channel are, respectively, 0.574, 0.528, and 0.544 eV for Ps(2)H(+), Ps(2)F(+), and Ps(2)Cl(+). Dissociation to several higher channels is also investigated. (c) 2005 Elsevier B.V. All rights reserved.