Positronium is just like an H-atom with the proton replaced by the positively charged anti-particle of the electron (called the positron which is as massive as the electron). What would be the ground state energy of positronium?
As in the new H - atom (positronium) proton is replaced by positron of mass m=2me as under Mass of positronium =m=mg−+mg+ mg+=mg−1=2mg As En=−13.6 and so energy of position En=8ε0n2h2−mg+g4=8ε0n2h2−[2me]e4=2−13.6 So En=213.6 [∵me=2m] En=−6.8eV
