The fixed-core stochastic variational method has been used to demonstrate t
he existence of an electronically stable ground state for potassium positri
de, KPs, with a binding energy of 0.003 275 Hartree. The 2 gamma annihilati
on rate of 2.001 x 10(9) s(-1) was almost the same as the annihilation rate
s computed previously for LiPs and NaPs. Analysis of the radial expectation
values, the annihilation rates and the e(-)-e(+) correlation function reve
al that KPs can be regarded as a Ps cluster moving in the field of the neut
ral atom.