POSITRONIC LITHIUM, AN ELECTRONICALLY STABLE LI-E(-STATE() GROUND)

Calculations of the positron-Li system were performed using the stocha stic variational method, yielding a minimum energy of -7.53208 hartree for the L = 0 ground state. In contrast with previous calculations of this system, the system was found to be stable against dissociation i nto the Ps + Li+ channel with a binding energy of 0.002 17 hartree; it is therefore electronically stable. This is the first instance of a r igorous calculation predicting that it is possible to combine a positr on with a neutral atom to form an electronically stable bound state.