Ground and excited states for exotic three-body atomic systems

An Angular Correlated Configuration Interaction method is extended and applied to exotic three-body atomic systems with general masses. A recently proposed angularly correlated basis set is used to construct, simultaneously and with a single diagonalization, ground and excited states wave functions which: (i) satisfy exactly Kato cusp conditions at the two-body coalescence points; (ii) have only linear parameters; (iii) show a fast convergency rate for the energy; (iv) form an orthogonal set. The efficiency of the construction is illustrated by the study a variety of three-body atomic systems [m(1)(-) m(2)(-) m(3)(z3+) ] with two negatively charged light particles, with diverse masses m(1)(-) and m(2)(-), and a heavy positively charged nucleus m(3)(z3+). The calculated ground 1(1)S and several excited n(1,3)S state energies are compared with those given in the literature, when available. We also present a short discussion on the critical charge necessary to get a stable three-body system supporting two electrons, an electron and a muon, or two muons.